Dr. Will Bulsiewicz Links Gut Microbiome to Hormone Control and Disease
The Diary Of A CEO
Diversifying plant fiber intake reshapes thirty-eight trillion gut microbes within twenty-four hours to regulate hormones, inflammation, and metabolic function.
## Background
This episode of The Diary Of A CEO was hosted by Steven Bartlett on YouTube and published on January 1, 2024. Featuring gastroenterologist Dr. Will Bulsiewicz, the video's description highlights a comprehensive deep dive into gut health, covering topics such as stool analysis, fiber, fecal transplants, and weight loss.
## TL;DR
In this episode, Dr. Will Bulsiewicz explains how the gut microbiome serves as a foundational ecosystem regulating human immune function, metabolic health, and hormonal balance. He discusses the significance of plant diversity, fiber, and fermented foods in nurturing over 38 trillion gut microbes, while addressing the limitations of calorie counting and synthetic weight-loss drugs. Furthermore, Dr. Bulsiewicz explores advanced topics such as fecal microbiota transplants, the estrobolome's impact on sexual health, and actionable dietary strategies to optimize gut health.
## Atmosphere & style
The conversation carries an engaging, intellectually stimulating, and conversational tone, balancing deep clinical expertise with accessible explanations. Steven Bartlett's curious, guided interviewing style allows Dr. Bulsiewicz to present complex gastroenterological concepts with warmth and clarity. The discussion moves seamlessly from urgent health warnings about gut dysfunction to grounded, encouraging insights into everyday nutrition and personal fulfillment.
## Key takeaways
- [05:32](https://www.youtube.com/watch?v=qqabbfk9wV8&t=332s) The human gut microbiome contains around 38 trillion microorganisms, primarily located in the colon, and functions as an essential partner in human survival.
- [13:35](https://www.youtube.com/watch?v=qqabbfk9wV8&t=815s) Approximately 70% of the human immune system resides within the walls of the intestines, where gut microbes train immune cells during early childhood.
- [13:35](https://www.youtube.com/watch?v=qqabbfk9wV8&t=815s) Damage to tight junctions in the intestinal barrier leads to a 'leaky gut', allowing foreign bacterial elements into the bloodstream and causing chronic inflammation.
- [17:41](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1061s) Major dietary changes can rapidly alter the human gut microbiome within 24 hours.
- [21:49](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1309s) Consuming at least 30 different plant foods per week across six categories is key to maximizing gut microbial diversity and overall health.
- [25:04](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1504s) Adding fermented foods to one's diet increases gut microbial diversity and helps reduce systemic inflammation.
- [28:40](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1720s) Prebiotics feed beneficial gut bacteria, which in turn produce short-chain fatty acids (postbiotics) like butyrate that regulate immunity and metabolism.
- [35:39](https://www.youtube.com/watch?v=qqabbfk9wV8&t=2139s) Transit time measured via tests like the 'Blue Poo' test serves as an important indicator of gut function and metabolic health.
- [40:24](https://www.youtube.com/watch?v=qqabbfk9wV8&t=2424s) Fiber intake must be increased gradually ('start low and go slow') to give gut microbes time to adapt and avoid gas or bloating.
- [43:58](https://www.youtube.com/watch?v=qqabbfk9wV8&t=2638s) Fecal microbiota transplants (FMT) demonstrate the potential to reverse specific medical conditions by restoring missing microbial species.
- [53:39](https://www.youtube.com/watch?v=qqabbfk9wV8&t=3219s) High-fiber and high-prebiotic diets naturally stimulate satiety hormones like GLP-1, offering a sustainable alternative or complement to weight-loss medications.
- [01:50:37](https://www.youtube.com/watch?v=qqabbfk9wV8&t=6637s) The estrobolome and specific bacteria like Clostridium scindens play major roles in regulating sex hormones, libido, and related health conditions.
## Detailed walkthrough
Here is a detailed, faithful walkthrough of this part of the conversation.
[00:00](https://www.youtube.com/watch?v=qqabbfk9wV8&t=0s) Intro: The Gut Health Epidemic and the Bristol Stool Chart
The episode opens with host Steven Bartlett presenting a visual array of different poop models, prompting Dr. Will Bulsiewicz to state that seeing certain shapes and colors is immediate grounds to consult a doctor. Dr. Will, a world-renowned gastroenterologist, outlines how humans are currently living through an epidemic of gut health issues. He explains that achieving true overall human health requires maintaining a healthy gut microbiome, which influences everything from weight loss and heart disease prevention to reducing cancer risk.
Dr. Will highlights that gut microbes directly govern mental health, noting that 95% of the body's serotonin—the primary "happy hormone"—is produced in the gut. The gut microbiome additionally controls cognition, memory, and daily energy levels. Addressing common health missteps, Dr. Will clarifies that hangovers are not merely a result of dehydration, but rather direct damage inflicted on the gut microbiome by alcohol. However, he offers reassurance: the gut is remarkably forgiving, and positive dietary choices made today will begin transforming the microbiome within just 24 hours.
- **Microbe density:** A single human thumb hosts as many microbes as there are people in the UK.
- **Serotonin production:** 95% of the body's happy hormone (serotonin) is produced by gut microbes.
- **Dietary impact:** Consuming the right fiber-rich foods allows people to eat until satisfied without restriction while still hitting weight goals.
[02:16](https://www.youtube.com/watch?v=qqabbfk9wV8&t=136s) Why Is the Gut Microbiome So Important?
Steven asks Dr. Will to give his elevator pitch to anyone on the fence about listening to the conversation. Dr. Will frames the discussion as potentially "life-transforming," emphasizing that modern society is experiencing a silent epidemic of gut dysfunction that extends far beyond standard digestive discomfort like bloating or constipation.
Dr. Will details his extensive medical background: he earned a chemistry degree from Vanderbilt University, attended Georgetown University School of Medicine, and completed a three-year internal medicine residency at Northwestern University, where he served as chief medical resident and won the program's highest award. He subsequently spent four years completing a gastroenterology fellowship. Today, in his role as the US Medical Director for the personalized nutrition company ZOE, he actively publishes clinical research papers on gut health.
- **Gastroenterology definition:** Dr. Will lightheartedly summarizes his specialty as focusing on "guts and butts"—covering everything from the esophagus to the colon.
- **Scientific timeline:** Awareness of the gut microbiome exploded around 2006–2007, shifting medical understanding from viewing health as a "black box" to recognizing microbes as the core drivers of human physiology.
[05:32](https://www.youtube.com/watch?v=qqabbfk9wV8&t=332s) What Are Gut Microbes?
Dr. Will breaks down what gut microbes actually are, describing them as an invisible, living ecosystem covering every inch of our external and internal surfaces. The highest concentration lives deep inside the large intestine (colon), housing roughly 38 trillion microorganisms—primarily bacteria, alongside fungi, parasites, and viruses.
```
+---------------------------------------------------------------------------------+
| THE HUMAN MICROBIOME AT A GLANCE |
+------------------------------------+--------------------------------------------+
| Total Colon Microbe Count | 38 Trillion Microscopic Organisms |
| Key Components | Bacteria, Fungi, Parasites, Viruses |
| Evolutionary History | > 1 Billion Years (Pre-dates Humans) |
| Immune System Residence | 70% of Immune Cells Live in Intestinal Wall|
+------------------------------------+--------------------------------------------+
```
He explains the origin of our microbiome: inside the womb, a fetus is largely protected, but the moment the mother's water breaks and the baby passes through the birth canal, it receives nature's foundational inoculum of microbes. This symbiotic partnership is the product of over a billion years of co-evolution. Dr. Will explains that while humans have only existed for three to four million years, microbes were the original life forms on Earth, and all complex life evolved around them.
- **The "Superorganism" concept:** Because human survival is impossible without these trillions of microscopic partners, humans are scientifically classified as superorganisms.
- **Historical example:** The "bubble boy" experiments of the 1970s demonstrated that attempting to raise a child in a sterile environment free of microbes severely impairs immune system development.
- **Crucial body systems governed by microbes:**
- **Immune system:** Microbes train immune cells during the first 3 years of life to prevent future allergies and autoimmune diseases.
- **Metabolism:** Regulates post-meal blood sugar and blood fat spikes.
- **Hormones:** Microbiome disruption is linked to endometriosis and PCOS in women, as well as erectile dysfunction in men.
[10:14](https://www.youtube.com/watch?v=qqabbfk9wV8&t=614s) Everyone's Microbes Are Different
Dr. Will reveals a striking contrast between human genetics and the microbiome. While any two human beings share 99.99% of the exact same human DNA, their gut microbiomes can be wildly distinct.
To illustrate this, he points to identical twins: despite sharing 100% of their genetic code, the same mother, and a nearly identical childhood environment and diet, identical twins share only about 25% of their gut microbes. The remaining 75% or more of their microbial makeup is completely unique to each twin.
- **Disease linkage:** Dr. Will asserts that virtually every patient entering a gastroenterology clinic presents with underlying microbiome damage.
- **Comorbidities:** When reviewing patient charts for specific gut issues like Irritable Bowel Syndrome (IBS), Crohn's disease, ulcerative colitis, or celiac disease, doctors almost always find a laundry list of co-existing systemic issues: high blood pressure, hyperlipidemia, type 2 diabetes, major depression, and autoimmune conditions.
[13:35](https://www.youtube.com/watch?v=qqabbfk9wV8&t=815s) Link Between the Immune System and the Gut
Addressing the connection between gut microbes and immunity, Dr. Will explains that 70% of the human immune system actually resides within the walls of the intestines. While immune cells are originally manufactured inside the bone marrow, they quickly migrate and take up permanent residence along the gut lining.
From an evolutionary perspective, this positioning is essential because the gut is the body's most vulnerable point of contact with the outside world. Unlike the skin, which functions as a dense, protective wall, the gut lining is an active decision-making center deciding what nutrients to absorb into the bloodstream and what toxins or pathogens to block.
- **The Epithelial Layer:** The barrier separating 38 trillion gut microbes on one side from 70% of the immune system on the other is astonishingly fragile—it consists of a single layer of cells held together by microscopic "cement" known as tight junctions.
- **Mechanism of chronic inflammation:** When these tight junctions break down (commonly referred to as a broken barrier or "leaky gut"), foreign bacterial elements leak directly into the bloodstream. This forces the immune system into a state of continuous, low-grade activation, driving the chronic inflammation underlying modern 21st-century chronic diseases.
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<Elicitation label="Understand the brain-gut connection" query="How does the gut microbiome directly influence mental health, mood, anxiety, and cognitive function according to Dr. Will?"/>
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Here is a detailed, faithful walkthrough of this section of the interview:
[15:45](https://www.youtube.com/watch?v=qqabbfk9wV8&t=945s) The Gut Barrier and Microbe Replication
Dr. Will Bulsiewicz explains that when the gut barrier is compromised, substances that are not supposed to enter cross over, leaving the immune system in a perpetual state of high alert as it constantly tries to clear them out. When asked how to repair this barrier, Dr. Bulsiewicz notes that the gut microbes are the ultimate stewards of the gut barrier. Every three to four days, the human body completely replaces and transforms its gut lining; the barrier a person has today is not the one they were born with, but one developed over the last few days. Gut microbes are essential in guiding and strengthening this rapid turnover.
Addressing a misconception, Dr. Bulsiewicz clarifies that while human intestinal lining cells turn over every three to four days, the gut microbes themselves replicate at a staggering rate—roughly every 20 minutes. He illustrates this power of exponential growth with an example: if you start with a single microbe in your intestines and feed it today, within 24 hours that single microbe will have spawned at least 1,000 new microbes. This demonstrates how rapidly dietary choices can amplify specific bacterial populations in the gut.
- **Gut Lining Turnover:** The human gut epithelial barrier completely replaces itself every 3 to 4 days.
- **Microbial Replication:** Gut microbes replicate roughly every 20 minutes, allowing 1 microbe to multiply into over 1,000 within a 24-hour window.
[17:41](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1061s) Food as Medicine and the Science of Microbe Adaptation
Steven Bartlett highlights a striking perspective from the introduction of Dr. Bulsiewicz's book: the average person consumes about 1.3 kg of food per day, which equals 475 kg per year and roughly 36,300 kg (over 36 metric tons) of food across a lifetime. Comparing this massive volume to the few milligrams of pharmaceutical medicine a person might take, Bartlett notes how food is the primary chemical input shaping physiological and gut health. Dr. Bulsiewicz agrees and points to a landmark 2014 study published in *Nature* by Dr. Lawrence David and colleagues at Duke University. Prior to this study, science knew diet changed the microbiome in mice, but it was unproven in humans. The researchers placed human subjects on diametrically opposed diets—a 100% plant-based diet versus a 100% animal-based diet—and discovered that significant shifts in the microbiome occurred within just 24 hours.
Dr. Bulsiewicz emphasizes that the gut is remarkably forgiving; while you cannot abuse it endlessly, no foods need to be strictly off-limits forever. The goal is to weight one's diet heavily toward high-quality foods. Because microbes are living organisms living inside the colon to access the nutrients humans ingest, what we put in our mouths dictates which bacterial families are fed and allowed to thrive. Different microbes prefer different foods—some thrive on kale, while others prefer simple sugars.
- **Lifetime Food Intake:** ~1.3 kg per day = 475 kg per year = ~36,300 kg over a lifetime.
- **2014 *Nature* Study (Lawrence David, Duke University):** Proved for the first time in humans that major dietary changes alter the gut microbiome in as little as 24 hours.
[21:49](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1309s) The Power of Plant Diversity and the "30 Plants" Rule
To optimize the gut microbiome, Dr. Bulsiewicz and fellow researcher Dr. Tim Spector advocate for plant diversity. Citing the American Gut Project (which included significant contributions from the British Gut Project), Dr. Bulsiewicz notes that the benchmark for optimal gut health is consuming 30 different plants per week. This includes a wide range across six categories: fruits, vegetables, whole grains, seeds, nuts, and legumes—not merely green leafy vegetables like kale.
Meeting patients where they are is critical; for someone currently eating 10 plant types a week (the average in Western countries like the US and UK), jumping straight to 30 can be overwhelming and unsustainable. Increasing incrementally—such as moving from 10 to 15—is a realistic milestone worth celebrating. Bartlett shares his personal experience running a Zoe gut test, which revealed he had a narrow, low-diversity microbiome compared to his partner's "Amazon rainforest" gut. Bartlett admits he is a creature of habit who reorders the same meals, whereas his partner constantly samples diverse, fermented foods.
- **Target Plant Diversity:** 30 different plants per week across fruits, vegetables, whole grains, seeds, nuts, and legumes.
- **Average Western Diet:** Most people in the US and UK consume only 10 to 15 distinct plants per week.
[25:04](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1504s) Fermented Foods: Sauerkraut, Pickles, and Stanford Research
Dr. Bulsiewicz describes fermented foods as a "lost art" in Western diets that can transform a low-diversity microbiome into a thriving ecosystem. He highlights a randomized controlled trial from Stanford University where participants who added fermented foods to their diet showed a clear increase in gut microbial diversity after just 8 weeks. He explains that all life has a microbiome—for instance, a fresh apple straight from an orchard carries around 100 million microbes that helped it grow and will eventually facilitate its natural breakdown.
Fermentation is the process of intentionally capturing and guiding this natural microbial activity to preserve and transform food. Using cabbage as an example, Dr. Bulsiewicz explains that simply chopping fresh cabbage, packing it into a mason jar with a sea salt brine, and leaving it in a cool spot for a week yields authentic sauerkraut. Unlike soft, canned store-bought sauerkraut, homemade fermented cabbage becomes crisp, tart, acidic, and complex. He notes that true pickles are similarly made by submerging whole cucumbers with their skin intact into salt water with dill, garlic, and peppercorns, allowing native surface microbes to ferment them—rather than simply soaking cucumbers in processed vinegar.
> "Fermentation is where we actually grab that process, and we control it. Almost like a magician, we're shaping it."
- **Stanford Fermented Food Study:** Showed increased gut microbiome diversity after 8 weeks of adding fermented foods.
- **Apple Microbiome:** A single fresh apple contains approximately 100 million microbes.
[28:40](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1720s) Demystifying Biotics: Prebiotics, Probiotics, and Postbiotics
To clear up common confusion, Dr. Bulsiewicz breaks down the definitions of the three key "biotics," noting that by definition, prebiotics and probiotics must demonstrate a proven beneficial health effect on human host biology:
* **Prebiotics:** Non-living dietary components (such as specific fibers and resistant starches) that serve as food for beneficial microbes. (Simple sugar feeds microbes but lacks health benefits, so it is not a prebiotic.)
* **Probiotics:** Live beneficial microorganisms (bacteria or yeasts) found in fermented foods or targeted clinical supplements that confer health benefits when consumed.
* **Postbiotics:** The non-living bioactive chemical compounds and metabolites produced by living gut microbes when they process prebiotics.
Dr. Bulsiewicz argues that the postbiotics are the ultimate driver of gut health benefits. Key examples include short-chain fatty acids (SCFAs) such as **butyrate**, **acetate**, and **propionate**. These SCFAs are manufactured when gut microbes ferment dietary fiber, and they serve as the primary fuel to repair and rebuild the gut barrier wall. While postbiotic pill supplements are emerging on the market, Dr. Bulsiewicz cautions that taking a synthesized postbiotic supplement in a capsule is not an equal substitute for consuming a high-fiber, plant-rich diet.
[32:04](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1924s) How Short-Chain Fatty Acids and the Microbiome Rule Your Metabolism
Dr. Will Bulsiewicz explains how short-chain fatty acids (SCFAs)—the primary postbiotics created when gut microbes ferment fiber—act as powerful cellular messengers throughout the entire human body. Rather than remaining confined to the gut wall where they reduce inflammation and reinforce mucosal barriers, these compounds cross into the bloodstream and traverse the blood-brain barrier. Through these pathways, SCFAs directly influence immune regulation and neurological health, driving home the concept that fiber's true value lies in fueling microbial SCFA production.
Turning to metabolism, host Steven Bartlett admits to the common misconception that metabolism is simply how quickly food passes through a person or whether someone is naturally thin. Dr. Will redefines metabolism as the body's baseline engine for managing energy currency, emphasizing how central the gut microbiome is to this mechanism. Referencing data from Zoe's PREDICT 1 study, Dr. Will points out that an individual's unique microbial composition heavily dictates their blood sugar spikes and blood fat responses after meals. SCFAs interact directly with cellular receptors to increase insulin sensitivity, reduce fat storage, enhance fat oxidation, and regulate visceral adiposity—the dangerous fat wrapped around internal organs in the abdomen.
- **Key SCFA Functions:** Crosses the blood-brain barrier to impact neurological pathways, boosts insulin sensitivity, reduces body fat storage, and increases fat burning.
- **The PREDICT 1 Study:** Research conducted via Zoe demonstrating that gut microbes predict individual post-meal blood glucose and blood lipid responses.
- **Visceral Adiposity:** Metabolic health, cholesterol levels, and abdominal fat distribution are directly regulated by the gut ecosystem.
---
[35:39](https://www.youtube.com/watch?v=qqabbfk9wV8&t=2139s) What Your Poo Says About Your Health and the "Blue Poo" Test
Addressing the cultural taboo surrounding bowel movements, Dr. Will points out that 60% of stool mass is composed of gut bacteria rather than merely undigested food waste. He draws a vivid parallel to cardiology: just as a cardiologist checks a patient's pulse or listens to their heart to gather vital signs, a gastroenterologist evaluates how a patient poops to gauge internal health. Stool provides a direct window into the gut's microbial composition and function.
To illustrate this connection, Dr. Will shares the methodology behind Zoe's "Blue Poo" study, published in the European gastroenterology journal *Gut*. Participants ate blue-dyed muffins, and researchers measured their "gut transit time"—the exact duration it took for the blue dye to travel from mouth to toilet bowl. The study established four distinct transit time categories: under 14 hours (very fast), 24 hours, 48 hours (both considered normal averages), and over 58 hours (very slow). Each group exhibited starkly different microbial ecosystems and levels of gut diversity. High-fiber consumers consistently landed in the middle normal zone, whereas low-fiber consumers drifted to the extreme ends, highlighting how fiber acts as an essential stool normalizer capable of resolving both diarrhea and constipation.
- **Composition of Stool:** 60% of stool by weight is composed of microbial organisms.
- **Blue Poo Study Cutoffs:**
- **Very Fast Transit:** Under 14 hours.
- **Normal Transit:** 24 to 48 hours (ideally once daily).
- **Very Slow Transit:** Over 58 hours.
- **Publication:** Published in the journal *Gut*, validating blue dye as a clinical benchmark over irregular markers like beet juice.
- **Fiber's Dual Action:** Fiber normalizes gut motility, correcting both rapid transit (diarrhea) and delayed transit (constipation).
---
[40:24](https://www.youtube.com/watch?v=qqabbfk9wV8&t=2424s) Fiber Adaptation: Why You Need to "Start Low and Go Slow"
Dr. Will addresses why so many people struggle when trying to increase their fiber intake, recounting his own experience ten years prior when eating a simple bowl of bean chili would leave him in doubled-over discomfort. Humans lack the digestive enzymes required to break down complex dietary fiber on their own; we are 100% reliant on gut microbes to do the heavy lifting for us. If a person has a damaged or depleted microbiome from years of a low-fiber diet, their microbes lack the capacity to process sudden influxes of roughage effectively.
To prevent gas, bloating, and abdominal pain, Dr. Will advises a "start low and go slow" approach. By gradually increasing fiber intake over weeks or months, people give their microbial population the necessary time to adapt, replicate, and build up their fiber-dicing machinery.
- **Human Digestive Limitation:** Humans produce zero native enzymes to digest complex fiber, relying entirely on microbial fermentation.
- **Dosing Strategy:** Incrementally increase fiber over a period of weeks to months to avoid severe abdominal distress.
---
[43:58](https://www.youtube.com/watch?v=qqabbfk9wV8&t=2638s) Fecal Transplants, Poop Capsules, and the Microbial Extinction Event
The conversation turns to fecal microbiota transplants (FMT). While FMT has achieved a massive success rate over the past decade in treating stubborn *Clostridioides difficile* (*C. diff*) infections, applying it to complex conditions like ulcerative colitis (an inflammatory bowel disease) has proved more challenging. However, Dr. Will highlights a landmark study where a small group of ulcerative colitis patients achieved complete disease remission after receiving FMT. Researchers discovered that all the successful cases had received stool from the exact same "super donor," suggesting that specific donor-recipient pairings may be required to treat distinct autoimmune and metabolic conditions.
Dr. Will outlines how FMT administration is evolving. The traditional method involves delivering liquid donor stool into the colon via a colonoscopy tube while the patient is under sedation. Newer technologies lyophilize (freeze-dry) stool into oral capsules—jokingly dubbed "poop pills." Looking ahead, Dr. Will envisions a pharmaceutical future where daily standardized microbial capsules reconstitute damaged gut biomes without invasive procedures.
The discussion takes a broader look at the global "microbial extinction event." Western populations have lost nearly half of the gut microbial species found in indigenous populations living traditional lifestyles in rural Africa. In response, international scientists are establishing "poop banks" to collect and preserve samples from remote tribal communities before those species disappear forever, creating a reserve that could one day restore depleted Western biomes. Steven and Dr. Will lightheartedly banter about the future monetary value of healthy stool, joking that in an automated, post-AI economy, high-quality human poop might become a prized commodity.
- **C. diff Success:** FMT remains an established, standard-of-care medical procedure for recurrent *C. diff* infections.
- **Super Donors:** Specific donor microbiomes hold the unique capacity to induce remission in diseases like ulcerative colitis.
- **Administration Methods:** Transitioning from invasive colonoscopies to freeze-dried, encapsulated oral pills.
- **Microbial Extinction:** Westerners possess roughly 50% less gut microbial diversity compared to indigenous, non-industrialized populations.
- **Stool Banking:** Global initiatives are currently archiving ancient microbial strains from rural tribal populations to safeguard against total loss.
[48:20](https://www.youtube.com/watch?v=qqabbfk9wV8&t=2900s) Fecal Transplants, Global Diets, and Prehistoric Microbes
Dr. Will Bulsiewicz highlights the remarkable trajectory of fecal microbiota transplants: a treatment once dismissed as worthless has transformed into a powerful clinical intervention for previously incurable hospital infections, serving as a cornerstone for the future of microbiome science. Steven Bartlett jokingly muses that this could restructure society's class system—where the upper class consists of people with the ultimate "super-poop" and the lower class comprises those with narrow, useless microbiomes.
Dr. Bulsiewicz finds the joke surprisingly fitting. In less-developed nations, lower economic status forces a reliance on basic staple foods like whole grains and legumes (such as beans and rice). Paradoxically, these affordable, traditional foods are packed with fiber, resistant starches, and polyphenols—all potent prebiotics that nourish gut microbes, leading to longer lifespans and lower disease rates. Steven quips that Westerners will soon sail off like old colonials, not for gold or diamonds, but to harvest high-quality poop. Dr. Bulsiewicz notes that battles already exist over fossilized prehistoric human poop; much like extracting mosquito DNA from amber in *Jurassic Park*, scientists hope to extract and study ancient microbial DNA to unlock lost gut health secrets.
- Legumes are high in fiber, resistant starches, and polyphenols, serving as essential prebiotics.
- Basic, low-cost staple diets (like beans and rice) cultivate rich microbial diversity compared to Western ultra-processed diets.
- Fossilized human stool offers a biological timeline, allowing researchers to study how the human microbiome has evolved and degraded over time.
---
[50:16](https://www.youtube.com/watch?v=qqabbfk9wV8&t=3016s) What Mouse Studies Reveal About the Microbiome
To prove the causal link between the gut microbiome and complex human conditions, researchers turn to controlled mouse models. By performing fecal transplants from humans into germ-free mice, scientists can observe whether specific traits or diseases transfer along with the gut bacteria.
Dr. Bulsiewicz highlights a landmark study involving identical human twins who shared the exact same genetic code, yet one was thin and the other was obese. When researchers transferred fecal samples from the twins into mice fed the exact same diet and calorie counts, the mice adopted the physical traits of their human donors: the mouse receiving the obese twin's microbiome gained weight, whereas the mouse receiving the thin twin's microbiome remained lean. This demonstrates that the microbiome governs how calories are processed—the obese microbiome operates like "swimming against the current," maximizing calorie absorption, while the lean microbiome operates like "swimming with the current at your back."
Similar transferability has been observed across various health conditions:
- **Diabetes:** Fecal transplants from non-diabetic human donors into diabetic recipients have been shown to improve human blood sugar parameters.
- **Ulcerative Colitis:** Transferring stool from human ulcerative colitis patients into mice reproduces the inflammatory bowel disease phenotype in the rodents.
- **Mental Health:** Transferring stool from humans suffering from anxiety, depression, or PTSD into mice transfers the corresponding behavioral and mood phenotypes.
---
[53:39](https://www.youtube.com/watch?v=qqabbfk9wV8&t=3219s) The Flaws of "Calories In, Calories Out" and the Power of Fiber
Steven asks what physically occurs inside the body to drive these metabolic differences. Dr. Bulsiewicz explains that microbes process food to produce short-chain fatty acids (SCFAs). A gut tailored to yield high levels of SCFAs regulates systemic metabolism, insulin sensitivity, blood lipids, and the genetic toggles for fat burning versus fat storage. Furthermore, individuals with healthier, fiber-fed microbiomes actually excrete more unabsorbed calories in their stool, while others burn more energy via thermogenesis.
This reality undermines the simplistic "calories in, calories out" weight loss model. While cutting calories forces short-term weight loss, the body compensates by slowing down its metabolic rate. This triggers aggressive hunger signals that inevitably lead to overeating and "yo-yoing" back above starting weights. Crucially, caloric restriction burns both fat and lean muscle mass, but weight regained comes back almost exclusively as fat, leaving the individual metabolically worse off.
Instead of restriction, Dr. Bulsiewicz advocates for an unrestrictive, high-prebiotic diet that naturally stimulates satiety hormones like GLP-1 and peptide YY (PYY). Ultra-processed foods bypass these fullness signals and drive overeating, leaving people feeling sluggish and metabolically disrupted. Returning to whole, fiber-rich plant foods allows the body to naturally regulate appetite.
- **Fiber Deficiency Gap:** 95% of Americans do not meet basic daily fiber recommendations.
- **Daily Intake Numbers:** The average American woman consumes only 15 g of fiber daily (recommended: 25 g); the average man consumes 18 g (recommended: 38 g).
- **Dietary Composition:** The average American gets only 10% of their daily calories from plant foods containing fiber.
---
[59:25](https://www.youtube.com/watch?v=qqabbfk9wV8&t=3565s) Weight-Loss Drugs (Ozempic) vs. Dietary Fiber
The conversation shifts to weight-loss drugs like Ozempic and Wegovy (semaglutide), which act as synthetic GLP-1 receptor agonists. While Dr. Bulsiewicz acknowledges their value for high-risk medical cases, he expresses strong concern over their widespread use as quick cosmetic fixes. Ozempic carries frequent gastrointestinal side effects, and because stopping the medication leads to immediate weight regain, patients face a potential lifelong commitment with unknown long-term health consequences.
Steven shares that many of his peers use these performance or weight-loss drugs for vanity rather than medical necessity, writing off risks. Dr. Bulsiewicz points out that relying on a costly drug skips the foundational step of building a healthy gut. Naturally increasing dietary fiber empowers gut microbes to produce SCFAs, which trigger the body's own release of GLP-1 and peptide YY without expensive prescriptions or unknown long-term risks.
Citing comprehensive meta-analyses by New Zealand researcher Dr. Andrew Reynolds, Dr. Bulsiewicz highlights the wide-ranging health benefits of increasing dietary fiber intake:
- Promotes natural, sustainable weight loss
- Lowers risk of heart attacks and fatal cardiovascular disease
- Reduces the incidence of stroke and Type 2 diabetes
- Decreases risk and mortality across multiple cancer types
- Improves blood pressure, glycemic control, and cholesterol levels
[01:04:04](https://www.youtube.com/watch?v=qqabbfk9wV8&t=3844s) Early Intervention vs. Root Cause Medicine
When discussing weight-loss medications and lifestyle interventions, the choice comes down to a fundamental medical framework: risk versus benefit. Every prescription drug carries inherent risks, but a major turning point in modern medicine comes from asking why doctors wait until a disease progresses to the point of needing a prescription. Intervening much earlier in a person's life can transform their health trajectory, either preventing disease altogether or making it far easier to manage.
While taking a medication to control a condition like Type 2 diabetes produces demonstrably better long-term outcomes than leaving it untreated, it functions as putting a sheet over the problem rather than fixing it. Adult-acquired Type 2 diabetes is highly reversible for many people through sustainable diet and lifestyle choices. Taking medication when necessary is appropriate, but addressing the root cause allows patients to eliminate drug dependence while building long-term health and vitality.
* Risk vs. Benefit: Every medication carries a trade-off, requiring doctors to evaluate if benefits outweigh potential harms.
* Reversibility: Type 2 diabetes is often reversible without permanent drug reliance when root causes are targeted.
* Preventive Vision: The goal of lifestyle medicine is to help individuals maintain high energy, health, and mobility well into their 80s.
---
[01:07:18](https://www.youtube.com/watch?v=qqabbfk9wV8&t=4038s) Stool as a Window into the Microbiome
Approximately 60% of the weight of human stool is microbial in origin, making daily bowel movements an accessible, cost-effective window into gut health without expensive testing. Using physical stool samples to illustrate, Dr. Will Bulsiewicz explains how size, shape, and consistency reflect internal digestive processes and the state of the gut microbiome.
While the Bristol Stool Scale was originally established in the 1990s based on a study of under 2,000 individuals in Bristol, recent large-scale research offers vast new insights. Through the "Big Poo Review" conducted in the UK with 142,000 participants completing a 17-question survey, researchers gathered comprehensive data on stool form, frequency, and related health conditions across the population.
* Average Frequency: The average individual in the UK poops **1.7 times per day**.
* Constipation Prevalence: **1 in 5 people** in the UK experience constipation.
* Diarrhea Prevalence: **1 in 6 people** in the UK suffer from diarrhea.
* The "Ideal" Stool: A **Bristol Type 4**—described poetically as a smooth, soft-formed sausage or torpedo—represents optimal gut function.
* Constipation Forms: Type 1 presents as hard, difficult-to-pass "rabbit pellets" or dense golf-ball-sized lumps, while Type 2 looks like individual marbles pressed together.
* Loose Forms: Type 5 features soft blobs, Type 6 presents as ragged fragments or a formless "cow pie," and Type 7 is entirely liquid.
---
[01:13:29](https://www.youtube.com/watch?v=qqabbfk9wV8&t=4409s) How Fiber and Transit Time Impact Stool Quality
Data from the Big Poo Review reveals clear correlations between diet and stool consistency. Individuals who consistently pass ideal Type 4 stools consume significantly higher amounts of dietary fiber and plant-based foods, such as legumes, whole grains, fruits, and vegetables. Conversely, diets high in fat and heavy in animal products correlate more frequently with constipation, whereas diets extremely rich in plant fiber generate short-chain fatty acids that act as natural lubricants, sometimes resulting in soft Type 5 stools without any underlying health issues.
```
FAST TRANSIT TIME SLOW TRANSIT TIME
(< 58 Hours to Liquid) (> 58 Hours / Dry Lumps)
[ Fast movement through colon ] [ Prolonged colon transit time ]
│ │
▼ ▼
[ Colon absorbs LESS water ] [ Colon absorbs MORE water ]
│ │
▼ ▼
[ Stool remains LIQUID/LOOSE ] [ Stool becomes HARD/DRY ]
(Types 6 & 7) (Types 1 & 2)
```
"If you want a window into your microbiome, look at your poop. You don't necessarily need to go and do an expensive test."
---
[01:16:32](https://www.youtube.com/watch?v=qqabbfk9wV8&t=4592s) Decoding Stool Colors and Medical Warning Signs
The natural brown color of human stool comes directly from bile, a digestive fluid produced by the liver and stored in the gallbladder to break down fats during meals. Changes in stool color reflect specific digestive processes, dietary habits, or medical conditions:
* **White / Clay-Colored:** Indicates a blockage in the bile ducts that prevents bile from mixing with food in the intestines.
* **Yellow:** Points to poor fat absorption or pancreatic issues, such as chronic pancreatitis; often accompanied by a visible oil slick floating on the toilet water.
* **Green:** Caused either by rapid infectious diarrhea (such as *Giardia* infection) or simply high consumption of chlorophyll-rich foods like green smoothies.
* **Blue:** Triggered by high intake of blueberries or artificial food dyes (such as the blue muffins used in gut transit tests).
[01:18:52](https://www.youtube.com/watch?v=qqabbfk9wV8&t=4732s) Red Stool, Early-Onset Colon Cancer, and Fiber's Protective Role
Dr. Will Bulsiewicz outlines a clear medical rule: seeing blood in your stool is never normal and warrants a conversation with a doctor. While red blood can stem from benign issues lower in the digestive tract—such as hemorrhoids or anal fissures—it can also indicate a rectal or colonic polyp, which is a precancerous precursor. Addressing these early via a colonoscopy can literally save lives by stopping cancer before it starts. Dr. Bulsiewicz emphasizes that colon cancer is the number two cause of cancer death in the US, with roughly 150,000 people diagnosed annually, despite being highly preventable.
Alarmingly, colon and rectal cancers are shifting toward much younger demographics. A person of Steven Bartlett’s generation is twice as likely to be diagnosed with colon cancer and four times as likely to be diagnosed with rectal cancer compared to their parents' generation. When Steven asks whether changing diets are driving this trend, Dr. Bulsiewicz agrees, noting a significant generational diet shift alongside a crucial microbiome connection. Fiber and short-chain fatty acids act as primary protective agents; referencing research by Professor Andrew Reynolds from New Zealand, Dr. B Bulsiewicz notes that for every 5-gram increase of daily fiber in one's diet, there is a statistically significant reduction in colorectal cancer risk.
- Bright red blood coating or mixed in stool usually stems from the rectum or lower GI tract (e.g., hemorrhoids, anal fissures, or polyps).
- Consuming beets can cause harmless red-tinted stool within 24 to 48 hours.
[01:22:22](https://www.youtube.com/watch?v=qqabbfk9wV8&t=4942s) Black Stool, Upper GI Bleeds, and the Olfactory Test
Turning to black stool, Dr. Bulsiewicz explains that it can arise from harmless sources or dangerous medical conditions. Taking bismuth subsalicylate (such as Pepto-Bismol) for an upset stomach frequently turns the stool black. However, a slow, high-up gastrointestinal bleed—such as bleeding in the stomach—will also produce black stool because the extended transit time through the long intestinal tract alters the blood from bright red to dark black.
The critical differentiator between harmless bismuth discoloration and an active upper GI bleed comes down to texture and smell. Blood that has traversed the digestive system turns into a dark, sticky, tar-like consistency (melena) and carries an unmistakable, highly foul odor. Dr. Bulsiewicz jokes that while patients do not need to stick their noses directly into the toilet, the scent of an upper GI bleed is so distinct that he can recognize it down the hospital hallway before even entering a patient's room.
- Bismuth subsalicylate (Pepto-Bismol) causes benign black discoloration of the stool.
- Upper GI bleeds produce black, tarry, extremely foul-smelling stool due to prolonged transit time.
[01:25:22](https://www.youtube.com/watch?v=qqabbfk9wV8&t=5122s) Microbiome Inheritance, Childhood Disruption, and Social Connection
When Steven asks how much of our gut microbiome is inherited from parents versus shaped by environment, Dr. Bulsiewicz explains that infants initially closely resemble their mother's gut microbiome. This microbial transfer is highest during traditional vaginal deliveries and through breastfeeding. When these natural processes are altered—such as through necessary C-sections, formula feeding, or early antibiotic use—it significantly influences the child's developing microbiome.
Disruptions to an infant's early microbiome development are linked to higher downstream risks of obesity, allergic conditions (such as asthma and food allergies), and autoimmune disorders (like celiac disease and type 1 diabetes). Researchers analyzing the gut microbiome in infant diapers at 6 to 12 months can even predict which children are more likely to develop allergic or autoimmune conditions four to five years later. However, Dr. Bulsiewicz reassures listeners—sharing that his own three children were born via C-section—that children can still grow up completely healthy despite these early disruptions.
Moving beyond infancy, Dr. Bulsiewicz presents striking new research showing that the human connections we maintain throughout life continuously shape our microbiome biology:
* **Co-habitation:** People living together share more microbes with each other than they do with their own genetic siblings.
* **Relationship Quality:** Couples with strong emotional connections share significantly more microbes than cohabiting couples who are emotionally distant or disconnected.
* **Physiological Impact:** Interpersonal relationships do not just impact our mental health; the people we surround ourselves with directly alter our physical gut biology.
* **Modern Screen Time:** Digital devices and social media often pull people away from face-to-face eye contact and real-world connection, depriving them of the physical gut-health benefits that come from genuine intimacy.
> "The power of human connection is more important in 2023, 2024... than it's ever been. Many aspects of our life are pulling us away from this... sit down with another person, look them in the eye, talk to them, have a meaningful conversation, and feel connected to that person, and because you feel connected, you reap the rewards, which do include better gut health."
[01:29:25](https://www.youtube.com/watch?v=qqabbfk9wV8&t=5365s) Stress, Trauma, and Healing the Mind-Gut Connection
Dr. Bulsiewicz details how emotional health directly manifests in physical gut symptoms. Acute stress—such as public speaking anxiety—can trigger nausea, stomach jitters, or severe abdominal cramping. When stress becomes chronic or stems from deep-rooted history, the biological impact on the gut becomes far more severe.
Research on two-year-old adopted children demonstrates that early trauma leaves a measurable mark on the gut microbiome, stress response pathways, and brain activation patterns (visible on fMRI scans) even before a child is old enough to consciously remember the experience. In his clinical practice, Dr. Bulsiewicz frequently encountered patients who diligently followed every diet, exercise, meditation, and lifestyle protocol but still suffered from chronic gut issues. Only after building trust and addressing underlying emotional trauma did their physical gut health finally resolve.
> "When you heal the wound of the trauma, you actually heal the gut. And it's amazing because they're like a rocket ship... The minute you take away this thing that is chaining them down and holding them back... they shoot to the moon. And it's like the greatest thing to see."
[01:32:59](https://www.youtube.com/watch?v=qqabbfk9wV8&t=5579s) The True Impact of Alcohol on Gut Microbes
When Steven shares that he recently quit drinking alcohol, Dr. Bulsiewicz applauds his choice. While acknowledging his own imperfect relationship with alcohol, Dr. Bulsiewicz states that the scientific evidence regarding alcohol's impact on gut health is clear: alcohol damages the microbiome.
Just as rubbing alcohol is used to sanitize surfaces because it destroys bacteria on contact, drinking alcohol acts as a direct antimicrobial agent within the gut ecosystem. Furthermore, Dr. Bulsiewicz refutes the common myth that hangover symptoms are purely caused by simple dehydration, pointing out that alcohol induces direct microvascular and cellular damage to the gut lining and its resident microbes.
[01:33:49](https://www.youtube.com/watch?v=qqabbfk9wV8&t=5629s) The Hidden Impact of Alcohol on Gut Health
The conversation opens with a stark warning about the true toll of alcohol on the human body, moving far beyond well-known risks like liver disease. Dr. Will Bulsiewicz criticizes standard official guidelines that deem moderate drinking acceptable up to three drinks a day for men or two for women, calling those thresholds "ridiculous." He points to a pivotal study that tracked levels of lipopolysaccharide (LPS), a toxic bacterial endotoxin, in relation to blood alcohol levels. LPS belongs inside the gut; its presence in the bloodstream is a direct indicator of a damaged, leaking gut barrier that triggers systemic inflammation and severe illness.
The study demonstrated that blood alcohol levels and bloodstream lipopolysaccharide levels rise and fall in perfect parallel lines. When blood alcohol spikes, endotoxins flood the blood; as blood alcohol decreases, endotoxins drop. For Dr. Will, this striking correlation transformed his perspective on drinking, proving that even minimal alcohol consumption inflicts immediate, measurable damage on the microbiome and gut lining. This acute disruption explains why it often takes 24 hours or longer after drinking to feel fully human again.
* **Lipopolysaccharide (LPS):** A bacterial endotoxin that should never enter the bloodstream; leaks through a damaged gut barrier to cause systemic inflammation.
* **Direct Correlation:** Blood alcohol levels and LPS endotoxin levels track each other as parallel lines.
* **Guideline Critique:** Dr. Will considers current moderate drinking guidelines (up to 3 drinks/day for men, 2 for women) far too high given the resulting gut barrier damage.
---
[01:35:31](https://www.youtube.com/watch?v=qqabbfk9wV8&t=5731s) The Brain-Gut Connection and Neurotransmitters
Dr. Will breaks down the intimate, constant communication between the brain and the gut, describing them as "inseparable best friends." A primary mechanism of this connection is the gut's immense production of neurotransmitters. While major depression is commonly treated by targeting brain serotonin, only 5% of the body's serotonin is actually produced in the brain—a staggering 95% is produced right in the gut. Serotonin regulates mood, energy, and focus. Additionally, 50% of the body's dopamine (the reward hormone) and over 30 other neurotransmitters originate in the digestive tract.
To deliver these messages, the gut relies on a direct communication line called the vagus nerve, which Dr. Will likens to a direct "super phone" connecting two people across the ocean. When the gut needs to alert the brain, it picks up this direct line without delay. Beyond neural wiring and neurotransmitters, the gut sends postbiotic metabolites—such as short-chain fatty acids (SCFAs) derived from fiber breakdown—across the blood-brain barrier. These SCFAs directly influence focus and mood; Dr. Will notes a study in children where boosting SCFA levels directly enhanced their ability to focus.
* **95% of Serotonin:** Produced in the gut, whereas only 5% is generated in the brain.
* **50% of Dopamine:** Produced in the gut along with more than 30 other distinct neurotransmitters.
* **The Vagus Nerve:** Functions as a direct, high-speed connection between the gut and the brain.
* **Short-Chain Fatty Acids (SCFAs):** Microbially produced postbiotics that cross the blood-brain barrier to regulate mood and focus.
---
[01:37:28](https://www.youtube.com/watch?v=qqabbfk9wV8&t=5848s) Short-Chain Fatty Acids and the "Gut as a Muscle" Metaphor
When host Steven Bartlett brings up Dr. Will’s book *Fiber Fueled*, where short-chain fatty acids are described as "the most healing nutrient in all nature," Dr. Will enthusiastically agrees, framing them as the most powerful anti-inflammatory molecules known to science. The process begins simply: we consume fiber or resistant starches, and our gut microbes act as "magicians" to ferment those foods into SCFAs. However, the story gets far more complex: human immune cells possess specific receptors designed to read these SCFA signaling molecules, allowing the gut microbiome to instruct the body on how to function, turn genes on or off, and calm down hyperactive immune responses.
Dr. Will highlights T regulatory cells, which depend on SCFAs to suppress improper immune attacks in autoimmune conditions. While autoimmune diseases carry a genetic component, genetics alone cannot explain why their incidence has skyrocketed by 500% over the last 50 years, as human DNA has not changed in that timeframe. Instead, modern dietary shifts away from fiber are driving these conditions. To rebuild capacity, Dr. Will compares the gut to a muscle. Just as someone bench-pressing weight must start at 50 kilos and progressively build up to 55 and 60 kilos, a person must introduce fiber "slow and low" to train their microbes and gradually unlock limitless digestive capability without restriction.
* **Immune Signaling:** Human cells feature dedicated receptors for SCFAs, allowing microbes to turn genes on/off and train the immune system.
* **T Regulatory Cells:** Activated by SCFAs to suppress overactive immune responses and mitigate autoimmune disease.
* **500% Increase:** The dramatic rise in autoimmune conditions over the last 50 years, pointing to environmental and dietary shifts rather than genetics.
* **"Slow and Low" Progressive Overload:** The gut acts like a muscle that must be gradually trained with diverse fibers to expand its processing capacity.
---
[01:41:02](https://www.youtube.com/watch?v=qqabbfk9wV8&t=6062s) Soluble vs. Insoluble Fiber
Addresssing whether all fiber is identical, Dr. Will explains that "fiber" is a broad umbrella term much like "protein"—no one considers the protein in a fish identical to the protein in a bean. Every individual plant species contains unique structural forms of fiber, creating a vast array of types that science has yet to fully catalog. Despite this underlying complexity, the primary distinction rests between two broad categories: soluble and insoluble fiber.
Soluble fiber dissolves completely in liquids, making it invisible to the eye; its chief function is serving as prebiotic fuel for beneficial gut microbes. Insoluble fiber provides "grit" and does not dissolve even if boiled. While insoluble fiber is generally not prebiotic, it plays vital physical roles: it optimizes bowel transit time, supports healthy bowel movements, assists with blood fat regulation, and helps lower cholesterol. Because every plant carries distinct fibers that feed distinct microbial families, eating a wide variety of plant foods ensures a thriving, diverse microbiome.
* **Soluble Fiber:** Dissolves in liquids and acts as prebiotic food for gut bacteria.
* **Insoluble Fiber:** Non-dissolving structural material that regulates transit time, bowel movements, cholesterol, and blood lipids.
* **Plant Specificity:** Every distinct plant species contains unique fiber types that feed specialized families of gut microbes.
---
[01:42:45](https://www.youtube.com/watch?v=qqabbfk9wV8&t=6165s) The "F GOALS" Framework for Gut Diversity
Dr. Will introduces his "F GOALS" framework, a daily mental checklist designed around dietary abundance rather than restrictive elimination diets—which he identifies as the single biggest misconception in gut health. The acronym lays out the core food groups essential for a thriving microbiome:
* **F – Fruit & Fermented Foods:** Fruits are unfairly villainized; higher fruit intake is linked to weight loss and reduced diabetes risk. Fermented foods add crucial microbial diversity.
* **G – Greens & Grains:** Greens deliver high nutrition with minimal calories, while unrefined whole grains supply fiber and resistant starches.
* **O – Omega-3 Super Seeds:** Chia seeds, flaxseeds, hemp seeds, and walnuts provide essential anti-inflammatory fats.
* **A – Aromatics:** Onions, garlic, and shallots feed microbes, protect heart health, and guard against cancer.
* **L – Legumes:** Beans, peas, and lentils are Dr. Will’s "#1 superfood" for gut health and longevity, consistently shown to lower risks of heart disease, cancer, stroke, and diabetes.
* **S – Superfoods (Shrooms, Seaweed, & Sprouts):** Mushrooms (fungi) and seaweed contain unique fibers. Sprouts—especially broccoli sprouts—are metabolic powerhouses. Unlocking seeds with water causes them to shoot up into sprouts packed with fiber, protein, and phytochemicals. Remarkably, broccoli sprouts contain 50 to 100 times more cancer-fighting sulforaphane than mature broccoli heads, meaning a single pinch offers the benefits of an entire head of broccoli.
---
[01:47:04](https://www.youtube.com/watch?v=qqabbfk9wV8&t=6424s) Intergenerational Loss of the Microbiome
The discussion shifts to how gut health is passed down across generations and how modern habits threaten this inheritance. Steven brings up a landmark study conducted by Dr. Justin Sonnenburg at Stanford University (who wrote a blurb for Dr. Will’s book *Fiber Fueled*). Because human generations span 30 or more years, Dr. Sonnenburg utilized mouse models to observe how a low-fiber Western diet impacts microbial diversity across successive generations.
The findings were striking: when mice were fed a low-fiber diet, their gut diversity dropped, and they passed this depleted microbiome down to their offspring. As those offspring remained on the same low-fiber diet, their diversity degraded even further before being handed down to the next generation. While introducing fiber back into later generations restored some dormant microbes, it could not recover the entire original spectrum—a portion of the ancestral diversity was permanently lost. Dr. Will illustrates this compounding loss with a stark generational example:
> "If your grandmother has 1,200 species of microbes in her gut as a child, but by the time your mother was born, she had 900, that's what your mother got. Then if your mother loses 300 species in her microbiome, now you start off with 600, half of what your grandmother [had]."
* **Justin Sonnenburg Study (Stanford):** Demonstrated that low-fiber diets cause progressive loss of microbiome diversity across generations in mouse models.
* **Incomplete Recovery:** Reintroducing fiber can reactivate dormant species, but cannot fully restore extinct microbial strains lost over generations.
* **Compounding Depletion:** Illustrates how inherited microbial diversity degrades from 1,200 species down to 600 species across just three generations under modern dietary patterns.
Here is a detailed, faithful walkthrough based on the transcript provided:
[01:49:08](https://www.youtube.com/watch?v=qqabbfk9wV8&t=6548s) Microbes, Intergenerational Health, and Lifestyle Transfer
The conversation addresses how the loss of specific gut microbial species becomes deeply problematic over time. Because each species evolved alongside humans for a distinct purpose, missing species leave functional gaps that remaining microbes cannot simply step up to fill. Maintaining gut health is not just an individual endeavor—it extends directly to raising healthy children and shaping the microbial ecosystem of the shared home environment.
Steven Bartlett and Dr. Will Bulsiewicz reframe generational health trends. While standard medical studies often attribute hereditary risks to genetic factors when diseases run in families, extensive research—much of it conducted by Dr. Tim Spector, Dr. Bulsiewicz’s partner at Zoe—reveals that pure genetics often fails to explain these patterns. Instead, what is passed down through generations is a combination of microbes and shared lifestyle choices. When an unhealthy lifestyle is inherited alongside a compromised microbiome that cannot cope with those habits, family health issues inevitably persist.
* **Key Takeaway:** Generational disease patterns are frequently driven by transferred lifestyle habits and shared microbial environments rather than purely genetic inheritance.
* **Expert Insight:** "When they're absent, they're not able to do their job. And the other microbes may not be able to step up to actually do what's the job of what's missing."
---
[01:50:37](https://www.youtube.com/watch?v=qqabbfk9wV8&t=6637s) The Gut Microbiome, Sex, Libido, and Matchmaking
The discussion shifts to sexual health, covering the link between gut microbes, hormonal regulation, libido, and attraction. When an individual is sick and suffering from gut dysbiosis, sexual desire is naturally suppressed. Hormonally, the gut microbiome exercises significant control over circulating estrogen in women via the "estrobolome"—a specific network of gut microbes that acts as a gatekeeper determining whether estrogen is excreted or recirculated back into the body. This mechanism explains why estrogen-driven conditions such as breast cancer, ovarian cancer, endometrial cancer, and endometriosis consistently display underlying gut microbiome damage.
A similar dynamic exists in men with androgens and testosterone. For instance, the bacterium *Clostridium scindens* directly influences male testosterone levels, while conditions like polycystic ovary syndrome (PCOS) in women stem from an estrogen-androgen imbalance centered in the gut. Beyond mechanics, Dr. Bulsiewicz suggests gut microbes play a subtle "matchmaking" role in human sexual attraction. Pheromone production, taste during kissing, and subtle body odors that signal compatibility or cause immediate turn-offs are deeply influenced by gut flora. Universal markers of physical attractiveness—radiant skin, body shape, and youthful appearance—are visible reflections of internal gut health.
* **The Estrobolome:** The collection of gut microbes capable of metabolizing and modulating circulating estrogen levels.
* **Bacterial Marker:** *Clostridium scindens* is tied to the regulation of male testosterone levels.
* **Hormone-Driven Conditions:** Breast cancer, ovarian cancer, endometrial cancer, endometriosis, and PCOS all feature documented gut microbiome disruptions.
* **Animal Findings:** Animal research demonstrates that individual pheromone profiles and attraction signaling are directly linked to gut microbes.
---
[01:56:53](https://www.youtube.com/watch?v=qqabbfk9wV8&t=7013s) Daily Microbiome Nutrition and 38 Tera
Steven shares that he has been sipping Dr. Bulsiewicz’s supplement, **38 Tera**, throughout the recording session. Dr. Bulsiewicz explains that the name "38 Tera" stands for 38 trillion, referring directly to the 38 trillion microbes residing inside the human gut. The flagship product, Daily Microbiome Nutrition, is a prebiotic powder designed with clinically proven ingredient dosages aimed at optimizing gut flora, reducing digestive symptoms, and guiding bowel movements back toward an ideal Bristol Stool Chart type 4 rating (from unhealthy 1, 2, 6, or 7 ratings).
Steven expresses surprise at how refreshing and delicious the drink tasted, noting he drank the entire bottle during their chat. Dr. Bulsiewicz notes that 38 Tera launches in mid-January across the United States and Australia via `38tera.com`, with international shipping options available for UK listeners while broader distribution is established based on demand.
* **Product Purpose:** Clinically dosed prebiotic powder to support gut flora, ease digestion, and standardize stool consistency to Bristol type 4.
* **Name Origin:** Named after the 38 trillion microorganisms forming the human gut microbiome.
* **Availability:** Distributed through `38tera.com`, launching initially in the US and Australia, with direct UK shipping available.
---
[01:58:44](https://www.youtube.com/watch?v=qqabbfk9wV8&t=7124s) Key Takeaways for Optimal Gut Health
Steven asks for a concise summary of actionable advice to wrap up the health portion of the conversation. Dr. Bulsiewicz outlines a clear, accessible foundational blueprint:
* **Eat a Wide Variety of Plants:** Incorporate diverse fruits, vegetables, whole grains, seeds, nuts, and legumes (even coffee counts toward plant diversity).
* **Include Fermented Foods:** Integrate fermented options regularly into your daily diet.
* **Lifestyle Essentials:** Exercise outdoors, prioritize good sleep, cultivate meaningful human connection, and hug loved ones.
* **Cost Factor:** Dr. Bulsiewicz points out that many of the most effective habits for supporting gut health and overall well-being are entirely free.
---
[01:59:16](https://www.youtube.com/watch?v=qqabbfk9wV8&t=7156s) Closing Podcast Tradition and Final Reflections
Following podcast tradition, Steven presents a question left by the previous guest without knowing who would answer it: *"When have you been happiest in your life?"*
Dr. Bulsiewicz reflects deeply on the nature of happiness, observing that modern society tends to over-fixate on measurable, objective metrics like financial wealth while overlooking unquantifiable personal fulfillment. He shares that his true happiness comes entirely from his family life away from the public eye—spending quality time with his loved ones, enjoying life together, and protecting them at his home in Charleston, South Carolina. Steven praises Dr. Bulsiewicz for his ability to translate complex science into accessible knowledge that increases public happiness and well-being.
Dr. Bulsiewicz directs listeners to connect with him online via Instagram and Facebook at `@TheGutHealthMD`, on TikTok at `@TheGutHealthMD_`, or through his website `theplantfedgut.com`, where he sends a free email newsletter breaking down new scientific research. Steven also announces an unprecedented addition to the show notes: a downloadable 10-page research brief compiled by his team summarizing the episode, alongside resources like the Bristol Stool Chart. The episode concludes with a brief sponsor note from Steven highlighting Huel products and his custom "Huel Steven Bundle."
* **Guest Social Handles:** `@TheGutHealthMD` (Instagram/Facebook), `@TheGutHealthMD_` (TikTok).
* **Website & Newsletter:** `theplantfedgut.com`
* **Location Reference:** Charleston, South Carolina.
* **Show Notes Bonus:** A 10-page research brief and actionable guide summarizing the entire interview.
[02:03:31](https://www.youtube.com/watch?v=qqabbfk9wV8&t=7411s) Huel Bundle Outro and Recommendation
Steven Bartlett wraps up the episode by sharing details about his custom "Steven's bundle" from sponsor Huel, highlighting its inclusion of a premium shaker and a specially designed T-shirt. He notes with some lighthearted amusement that many of his friends have commented on the T-shirt being "the best quality T-shirt they've ever had," pointing out how surprisingly flattering it fits. Listeners are directed to find the link to the bundle directly in the podcast description, regardless of what platform they are listening on.
To close out the show, Bartlett leaves the audience with a personalized recommendation for their next listen. He reveals that internal listener data shows people who enjoyed this conversation with Dr. Will Bulsiewicz also "tend to absolutely love" another specific recent episode. He encourages viewers and listeners to check out the provided link in the show notes to continue their deep dive into health and wellness topics.
- Features the custom "Steven's bundle" from sponsor Huel, containing the daily greens shaker and exclusive apparel.
- Directs the audience to related content linked in the episode description based on listener preference trends.
## Notable quotes
> [25:04](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1504s) Fermentation is where we actually grab that process, and we control it. Almost like a magician, we're shaping it. — Dr. Will Bulsiewicz
> [01:49:08](https://www.youtube.com/watch?v=qqabbfk9wV8&t=6548s) When they're absent, they're not able to do their job. And the other microbes may not be able to step up to actually do what's the job of what's missing. — Dr. Will Bulsiewicz
> [01:59:16](https://www.youtube.com/watch?v=qqabbfk9wV8&t=7156s) When have you been happiest in your life? — Steven Bartlett
## Mentioned
Steven Bartlett, Dr. Will Bulsiewicz, The Diary Of A CEO, Vanderbilt University, Georgetown University School of Medicine, Northwestern University, ZOE, American Gut Project, British Gut Project, Tim Spector, Stanford University, Lawrence David, Duke University, Nature, Gut, Ozempic, Wegovy, Clostridium scindens, 38 Tera, Bristol Stool Chart, Huel
Dr. Will Bulsiewicz 揭示肠道微生物组与激素调控及疾病的关联
丰富植物纤维摄入可在24小时内重塑38万亿个肠道微生物，进而调节激素、炎症和代谢功能。
在本期节目中，Dr. Will Bulsiewicz 阐述了肠道微生物组如何作为基础生态系统，调节人体免疫功能、代谢健康与激素平衡。他探讨了植物多样性、纤维及发酵食品在滋养超过38万亿个肠道微生物中的重要意义，同时指出了计算卡路里与合成减肥药物的局限性。此外，Dr. Bulsiewicz 还深入探讨了粪菌移植、雌激素菌群（estrobolome）对性健康的影响等进阶话题，并提供了优化肠道健康的可行饮食策略。
人体结肠内寄宿着约38万亿个微生物，其中约70%的免疫系统位于肠壁，紧密连接受损导致的“肠漏”会引发外来细菌成分入血并诱发慢性炎症。 (5:32)
肠道菌群更新极快，饮食的重大改变在24小时内即可重塑人体肠道微生物群。 (17:41)
每周摄入涵盖6大类的至少30种不同植物性食物，并搭配发酵食品，能显著提升肠道微生物多样性并减轻全身性炎症。 (21:49)
益生元可喂养有益肠道细菌，促使其生成丁酸等短链脂肪酸（后生元），从而调节免疫与代谢，并通过“蓝便测试”评估的肠道转运时间是衡量肠道功能的重要指标。 (28:40)
Reading summary
Gastroenterologist Dr. Will Bulsiewicz argues that the gut microbiome functions as the primary regulator of human metabolism, immunity, and mental health, with dietary plant diversity acting as the most effective tool to restore it. Rather than relying on restrictive caloric diets or pharmaceutical quick fixes, long-term health depends on feeding colon bacteria to maintain the intestinal barrier and stimulate anti-inflammatory metabolites.
The Biological Architecture of the Gut (5:32)
The human colon contains roughly 38 trillion microorganisms, an evolutionary partnership that co-developed alongside complex life. Despite humans sharing 99.99% of identical DNA, gut microbiomes differ widely; even identical twins share only about 25% of their microbes. Crucially, roughly 70% of the human immune system resides along the intestinal wall, separated from this dense microbial population by an epithelial barrier only a single cell thick. This barrier turns over completely every three to four days, actively guided by microbes replicating as rapidly as every 20 minutes.
Metabolism, Short-Chain Fatty Acids, and Weight Regulation (32:04)
When gut microbes ferment prebiotic dietary fiber, they generate short-chain fatty acids (SCFAs) such as butyrate, acetate, and propionate. These postbiotics cross into the bloodstream and through the blood-brain barrier, acting as signaling molecules that enhance insulin sensitivity, prompt fat oxidation, and govern visceral adiposity. Dr. Bulsiewicz challenges the traditional 'calories in, calories out' model, pointing to fecal transplant studies where germ-free mice fed identical calories adopted the lean or obese physical phenotypes of human twin donors.
The Gut-Brain Connection and Neurochemistry
Communication between the digestive system and the brain operates continuously via the vagus nerve and circulating metabolites. An estimated 95% of the body's serotonin and 50% of its dopamine are generated in the digestive tract rather than the brain, positioning the microbiome as a direct governor of daily mood, cognitive focus, and energy. Dr. Bulsiewicz highlights that psychological trauma and chronic stress can directly destabilize gut ecology, while biological disruptions such as alcohol intake prompt intestinal wall leakage and trigger systemic endotoxemia.
Dietary Strategies: The 30-Plant Benchmark (21:49)
Drawing on data from the American Gut Project, Dr. Bulsiewicz recommends consuming at least 30 different plant foods weekly across six categories: fruits, vegetables, whole grains, seeds, nuts, and legumes. Because humans lack native enzymes to break down complex dietary fibers, gut bacteria handle digestion entirely. For individuals transitioning from low-fiber diets, an incremental 'start low and go slow' approach is advised to allow bacterial populations to replicate without causing severe bloating or gas. Integrating fermented foods also systematically boosts microbial diversity within eight weeks.
Stool Quality and Clinical Warning Indicators (67:18)
Because approximately 60% of stool weight consists of gut bacteria, bowel movements provide a direct clinical window into internal physiology. Research from the UK 'Big Poo Review' demonstrates that ideal Bristol Stool Scale Type 4 movements correlate strongly with high dietary plant fiber intake. Visual indicators serve as diagnostic flags: clay-colored stool points to bile duct blockages, yellow oily stool indicates impaired fat absorption, while sticky, foul-smelling black stool or visible red blood warrants medical evaluation for gastrointestinal bleeding or precancerous colorectal polyps.
Microbial Extinction and Generational Loss (43:58)
Western populations face a progressive 'microbial extinction event,' carrying roughly half the gut microbial species found in rural indigenous populations. Referencing mouse research led by Dr. Justin Sonnenburg at Stanford University, Dr. Bulsiewicz emphasizes that low-fiber diets permanently strip microbial diversity across successive generations, as offspring inherit progressively narrower biomes. Because unshared genes fail to account for many family health trends, transferring degraded microbial ecosystems alongside unhealthy lifestyle habits likely drives recurrent generational disease patterns.
While the gut microbiome possesses rapid plasticity—transforming significantly within 24 hours of targeted dietary changes—modern Western diets risk inducing irreversible species extinctions across generations. Dr. Bulsiewicz maintains that prioritizing plant diversity and lifestyle factors offers an accessible root-cause approach, though targeted clinical interventions such as fecal microbiota transplants remain necessary to resolve severe ecological collapse.
精炼阅读摘要
消化病学专家 Will Bulsiewicz 博士指出，结肠内约38万亿个微生物是调控人体免疫、代谢与精神状态的核心中枢。他主张现代健康危机本质上是肠道微生态受损，通过大幅提升植物多样性与发酵食品摄入，可促使菌群生成短链脂肪酸以修复肠道屏障并系统性预防慢性疾病。
肠道屏障、免疫系统与脑肠轴连接 (13:35)
Dr. Will 解释，结肠深处的38万亿微生物与人体约70%的免疫细胞仅由一层单细胞厚的肠上皮层隔开，细胞间依靠紧密连接维系。人体上皮细胞每3至4天更新一次，而肠道微生物约每20分钟分裂一代，因此菌群直接指导着肠壁屏障的修复。当紧密连接破损形成“肠漏”时，细菌内毒素（如脂多糖 LPS）会渗漏入血，激发持续的低度全身性炎症，成为心血管疾病、2型糖尿病及抑郁症等现代慢性病的潜在诱因。
此外，肠道与大脑通过迷走神经及化学信号保持紧密联动。人体内约95%的五羟色胺（血清素）和50%的多巴胺在消化道产生，并伴随30多种神经递质。Dr. Will 指出，酒精不仅是表面消毒剂，摄入后还会直接杀伤肠道共生菌群，实验显示血液酒精浓度与有害内毒素 LPS 渗入血液的水平呈平行正相关；同时，童年创伤与慢性心理压力也会在肠道微生态留下持久印记，导致常规饮食调理难以奏效，唯有解除深层情绪创伤方能修复消化功能。
短链脂肪酸、代谢调控与热量平衡逻辑 (32:04)
人类自身缺乏分解复杂膳食纤维的酶，完全依赖肠道微生物将其发酵生成后生元（Postbiotics），其中以丁酸、乙酸和丙酸等短链脂肪酸（SCFAs）最为关键。短链脂肪酸不仅是肠黏膜修复的主要能源，还能穿透血脑屏障，激活免疫调节性 T 细胞以遏制异常免疫攻击。Dr. Will 强调，过去50年间自身免疫疾病增加了500%，在人类基因组未发生改变的情况下，这一剧增主要归咎于现代饮食中纤维摄入的急剧萎缩。
在能量代谢方面，短链脂肪酸可提升机体胰岛素敏感性、抑制脂肪储存并加速内脏脂肪氧化。Zoe 开展的 PREDICT 1 研究及人类双胞胎粪菌移植小鼠实验表明，供体菌群特征能直接决定受体对热量的利用模式与体型表型：健康的菌群促使机体随粪便排出更多未吸收热量，并天然诱导饱腹激素 GLP-1 与 PYY 的释放。Dr. Will 批评了单纯限制热量的“卡路里进出”理论以及将降糖药物 Ozempic 盲目用作外貌减重工具的现象，警告骤停药物会导致体重反弹且多为脂肪堆积，而天然高纤维饮食能免除药物依赖建立内源性代谢稳态。
植物多样性原则、发酵饮食与渐进适应 (21:49)
依据美国肠道项目等大型队列数据，Dr. Will 与科研团队建议将每周摄入30种不同植物设定为肠道健康基准，范畴覆盖水果、蔬菜、全谷物、坚果、种子和豆类六大门类。针对英美等西方国家居民平均仅摄入10至15种植物的现状，他强调不应急于求成，而应采用“低起点、慢加速”的增量过渡法，以便给退化的菌群留出繁殖酶系和扩增种群的时间，防止一次性摄入过多糙料引起严重腹痛与胀气。
发酵食品被其视作快速唤醒微生态多样性的核心干预手段。斯坦福大学一项随机对照研究表明，持续8周增加发酵食品（如天然盐水发酵酸菜与泡菜）可显著提高人体肠道菌群的多样性。在饮食结构构建上，Dr. Will 提出了涵盖水果与发酵食品（F）、绿叶蔬菜与全谷物（G）、富含Omega-3的超级种子（O）、葱蒜类香辛料（A）、豆类（L，被其列为头号长寿食物）以及菌菇、海藻与西兰花嫩苗等超级食物（S）的“F GOALS”实践框架。
粪便生理指标、警示信号与菌群代际流失 (67:18)
人体粪便干重的60%为微生物菌体，是评估内部微生态最直观的临床窗口。结合涉及14.2万人的“大便调查”与 Zoe 开展的“蓝便转运时间测试”，结肠转运时间在24至48小时且呈布里斯托大便分类法第4型（光滑香肠状）为最佳状态，富含纤维的膳食具有双向调节功能。Dr. Will 强调排便颜色具有关键医学筛查价值：陶土样白便提示胆管受阻，黄色浮油粪便反映胰腺消化不良，而柏油样极度恶臭的黑便通常是上消化道出血的征象；粪便带鲜红血迹则绝非正常现象，需警惕下消化道病变或直肠息肉。研究显示年轻一代直肠癌风险显著攀升，但循证医学数据显示每日增加5克纤维摄入便能显著降低结直肠癌患病风险。
在生态演化层面，菌群的多样性正面临代际丧失的危机。斯坦福大学 Justin Sonnenburg 博士在小鼠实验中证实，长期低纤维饮食造成的菌群灭绝会随繁殖代代放大，且后代重新恢复纤维摄入也无法逆转部分祖传菌种的彻底灭失。这一发现解释了现代家庭中代谢与免疫疾病的聚集现象，其诱因往往并非单纯的遗传基因，而是代际共享的不良生活方式与持续劣化的微生态环境相互叠加所致。
Dr. Will 倡导现代医疗应从被动的末端处方控制，转向以修护微生态为核心的早期生活方式医学。尽管增加高纤饮食、补充发酵食品及日常监测粪便性状提供了低成本的健康管理途径，但患者仍需建立循序渐进的适应节奏；针对便血、持续消瘦或器质性胃肠异常，膳食调理与益生元补剂无法替代规范的内镜排查与专业医疗诊断。
Detailed notes — zh
## Background
本期节目于 2024 年 1 月 1 日由知名访谈频道《The Diary Of A CEO》（主持人 Steven Bartlett）发布于 YouTube 平台。节目简介指出，本次访谈邀请了著名胃肠病学专家威尔·布尔谢维奇博士（Dr. Will Bulsiewicz），深入探讨排便形态所揭示的身体警讯、肠道微生物组与免疫系统的紧密关联、如何通过多样化植物饮食与发酵食物修复肠道，以及脑肠轴对全身代谢和身心健康的深远影响。
## TL;DR
胃肠病学家 Dr. Will 深入剖析了结肠内 38 万亿微生物构成的“超级有机体”，阐述其如何直接调控人体 70% 的免疫防御、代谢平衡以及包括 95% 血清素合成在内的大脑神经功能。访谈指出，大便的形态（布里斯托分型）与转运时间是了解体内菌群状态的直观晴雨表，而血便、黑便等异常特征则是必须就医的严重信号。针对现代人的代谢紊乱与超加工食品陷阱，单纯计算卡路里或依赖 Ozempic 等减重药物难以解决根本病因，最根本的解法在于遵循以“每周摄入 30 种植物”为代表的 F-GOALS 高纤维饮食框架，借助肠道菌群发酵产生的短链脂肪酸（SCFAs）构筑全身抗炎屏障。此外，对话还揭示了亲密关系、童年心理创伤、饮酒以及代际微生态流失对肠道健康的深层生理印记。
## Atmosphere & style
整场对话在严密扎实的临床医学科研与诙谐生动的日常隐喻之间自如切换，演播室桌面上形态逼真的便便模型彻底打破了大众对排泄生理的禁忌与羞耻感。Dr. Will 兼具顶尖学者的专业严谨与罕见的沟通感染力，与主持人 Steven 好奇、敏锐且充满代入感的互动碰撞出极具启发的火花。对谈不仅涵盖了对生物学机制和临床试验的硬核拆解，更在深入剖析创伤疗愈对肠道新生的赋能、以及探寻家庭幸福本质时升华出温暖动人的医者人文情怀，给观众带来颠覆认知且充满行动力量的健康启蒙。
## Bulletin
- [13:35](https://www.youtube.com/watch?v=qqabbfk9wV8&t=815s) 肠道并非单纯的消化器官，人体 70% 的免疫细胞驻扎在肠壁，且 95% 的血清素和 50% 的多巴胺均由肠道合成，直接调控全身代谢、情绪与大脑认知。
- [18:49](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1129s) 杜克大学研究证实，饮食改变在 24 小时内就会显著重塑肠道菌群；维持微生态多样性的黄金准则是每周摄入至少 30 种不同的植物性食物。
- [31:19](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1879s) 肠道菌群发酵膳食纤维生成的短链脂肪酸（SCFAs）是天然抗炎与代谢调控分子，能修复单层上皮细胞屏障并自主刺激天然饱腹激素 GLP-1 的分泌。
- [01:06:59](https://www.youtube.com/watch?v=qqabbfk9wV8&t=4019s) 大便干重的 60% 为微生物，布里斯托大便分类法第 4 型（光滑香肠状）为黄金标准，便血或柏油样黑便往往是直肠息肉、结直肠癌或上消化道出血的严重警讯。
- [01:33:46](https://www.youtube.com/watch?v=qqabbfk9wV8&t=5626s) 宿醉的核心生理机制是酒精破坏肠道屏障，导致脂多糖（LPS）内毒素漏入血液循环引发全身急性炎症，绝非单纯脱水问题。
## Key takeaways
- [13:35](https://www.youtube.com/watch?v=qqabbfk9wV8&t=815s) 肠道是包含约 38 万亿微生物的共生生态系统，仅依靠单层上皮细胞与人体 70% 的免疫系统隔开，屏障受损会导致系统性慢性炎症。
- [10:14](https://www.youtube.com/watch?v=qqabbfk9wV8&t=614s) 人类基因相似度高达 99.99%，但即便是同卵双胞胎，其肠道微生物的重合度也仅约 25%，肠道菌群呈现极大的后天塑造性与个体差异。
- [20:15](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1215s) 饮食能在 24 小时内迅速重塑菌群构成；建立肠道健康的基石在于植物多样性，建议每周摄入 30 种涵盖水果、蔬菜、全谷物、坚果和豆类的植物。
- [25:39](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1539s) 发酵食品集益生菌、益生元与后生元三重益处，斯坦福大学临床试验证实日常引入发酵饮食能在 8 周内显著提升菌群多样性。
- [31:19](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1879s) 短链脂肪酸（丁酸、乙酸、丙酸）是肠道菌群分解纤维的关键产物，具备跨越血脑屏障、激活脂肪代谢与平抑全身炎症的修复功能。
- [38:39](https://www.youtube.com/watch?v=qqabbfk9wV8&t=2319s) 通过蓝色松饼测试测算肠道转运时间，理想区间约为 24 至 48 小时；膳食纤维是世界上唯一能对便秘与腹泻产生双向调节的营养素。
- [40:06](https://www.youtube.com/watch?v=qqabbfk9wV8&t=2406s) 人体自身缺乏分解膳食纤维的酶，完全依赖微生物代谢；增加纤维摄入需遵循“低起步、稳增加”原则，像锻炼肌肉一样训练肠道耐受度。
- [50:16](https://www.youtube.com/watch?v=qqabbfk9wV8&t=3016s) 粪菌移植（FMT）已成功应用于艰难梭菌治疗，动物模型更证实肥胖、糖尿病及情绪表型可经由菌群精准转移，揭示了代谢背后的微生物主导权。
- [59:25](https://www.youtube.com/watch?v=qqabbfk9wV8&t=3565s) 高纤维饮食能天然刺激肠道分泌饱腹激素 GLP-1 与 PYY，相比单纯依赖降糖减重药物 Ozempic，调整天然饮食能从根源重塑代谢且避免肌肉流失与反弹。
- [01:10:05](https://www.youtube.com/watch?v=qqabbfk9wV8&t=4205s) 布里斯托大便分类法中，表面光滑成型的第 4 型是肠道健康的黄金基准；严重便秘（第 1 型）与腹泻（第 7 型）在饮食结构上往往均呈现纤维严重匮乏。
- [01:15:56](https://www.youtube.com/watch?v=qqabbfk9wV8&t=4556s) 排便颜色是内脏健康的晴雨表：白色提示胆道阻塞，黄色油腻便关联胰腺消化酶不足，柏油样黑便预示上消化道出血，而血便必须及时就医以排查结直肠癌。
- [01:25:22](https://www.youtube.com/watch?v=qqabbfk9wV8&t=5122s) 早期微生态定植对免疫至关重要，自然分娩与母乳喂养奠定基石，剖宫产与婴儿期滥用抗生素可能增加未来患肥胖、过敏及自身免疫病的几率。
- [01:29:25](https://www.youtube.com/watch?v=qqabbfk9wV8&t=5365s) 深层情绪与童年创伤会通过脑肠轴在神经和微生态上留下烙印，成为阻碍身体自愈的无形枷锁，心理创伤的疗愈往往是攻克顽固肠道疾病的前提。
- [01:33:46](https://www.youtube.com/watch?v=qqabbfk9wV8&t=5626s) 宿醉的本质是酒精杀灭微生物、破坏肠道屏障并导致内毒素入血引发急性炎症，血液中酒精浓度与内毒素 LPS 浓度呈高度平行上升。
- [01:35:31](https://www.youtube.com/watch?v=qqabbfk9wV8&t=5731s) 迷走神经是脑肠即时双向沟通的超级专线，肠道制造了全身 95% 的血清素与 50% 的多巴胺，直接掌管精力、情绪与心理专注力。
- [01:42:55](https://www.youtube.com/watch?v=qqabbfk9wV8&t=6175s) 践行“F GOALS”高纤维植物饮食框架（水果发酵物、绿叶谷物、Omega-3 种子、葱属蔬菜、豆类、菌菇海藻芽菜），以加法思维丰富日常餐盘。
- [01:50:37](https://www.youtube.com/watch?v=qqabbfk9wV8&t=6637s) 肠道菌群中的“雌激素组（Estrobolome）”负责调控体内雌激素的循环与排出，其微生态失调与乳腺癌、子宫内膜异位症及 PCOS 等激素疾病密切相关。
## Detailed walkthrough
### [00:00](https://www.youtube.com/watch?v=qqabbfk9wV8&t=0s) 便便形态、隐形微生物与肠道健康危机
访谈以一系列引人注目的便便模型道具开场。Dr. Will Bulsiewicz 看着桌上形态各异的模型直言，便便的形状和质地正是身体内部状况的直观晴雨表，如果排泄物呈现出某些特定病态特征，“那就是必须去看医生的明确信号”。当下人类正身处一场广泛蔓延的“肠道健康危机”之中，若想拥有真正的身心健康，健康平衡的肠道微生物组是绝对不可或缺的前提。肠道微生态的影响力远超普通人的想象：人体大拇指上附着的微生物数量，就相当于整个英国的人口总数；人体内高达 95% 的“快乐荷尔蒙”（血清素）是在肠道中合成的，它直接调控着人类的抑郁风险、认知功能、记忆力与精力水平。
在生活方式与饮食方面，科学界已有大量研究证实，通过优化饮食来滋养肠道菌群，不仅能有效减重，还能显著降低心血管疾病及多种癌症的死亡风险。针对日常生活中常见的饮酒与宿醉，Dr. Will 澄清了大众认知中的误区：宿醉绝不仅仅是身体脱水那么简单，其核心本质在于过量酒精对肠道微生态造成了剧烈破坏。不过，肠道具有极强的自愈力与韧性，人们今天所做出的饮食选择，在 24 小时之内就会对肠道菌群产生立竿见影的积极反馈。
主持人 Steven Bartlett 在进入深度对谈前插播了一段真诚的呼吁。后台数据显示，频道长期常客中仍有高达 69.9% 的观众尚未点击订阅。他诚挚恳请喜爱本期内容的观众按下订阅键，以帮助团队持续邀请重量级嘉宾、提升制作水准，并承诺将以更优质的节目内容回馈所有支持者。
```mermaid
flowchart TD
accTitle: 肠道微生态对人体系统的全方位影响
accDescr: 展示肠道微生物如何通过神经、代谢、免疫等途径影响全身健康。
subgraph Gut["肠道微生态系统"]
M["38万亿 肠道微生物 (结肠)"]
end
subgraph Brain["神经与大脑"]
B1["合成 95% 快乐荷尔蒙 (血清素)"]
B2["调控认知、记忆与情绪"]
end
subgraph Metabolism["代谢与免疫"]
M1["餐后血糖与血脂响应"]
M2["免疫系统训练与防过敏"]
end
M --> Brain
M --> Metabolism
```
---
### [02:13](https://www.youtube.com/watch?v=qqabbfk9wV8&t=133s) 肠道健康的流行病与 Dr. Will 的医学学术履历
当被问及如果观众刚刚点进这期节目、正在犹豫是否继续收听，该如何向他们推荐时，Dr. Will 充满信心地表示，这将会是一场“彻底改变人生的对话”。肠道健康问题如今已演变成全人类层面的流行病，腹胀、便秘、消化不良等症状比比皆是。但肠道的意义绝不仅局限于食物消化本身，如果人类想实现健康长寿这一最高人生目标，就必须优先修复和照料肠道微生物。
谈到自己的学术与专业履历，Dr. Will 展现了极为扎实且耀眼的医学科研底蕴：
- **本科阶段**：以优异成绩毕业于范德堡大学（Vanderbilt University），获得化学学位。
- **医学教育**：随后进入全美顶尖的乔治城大学医学院（Georgetown University School of Medicine）深造并获得医学博士学位。
- **住院医师培训**：在西北大学（Northwestern University）完成为期 3 年的内科住院医师培训，期间荣获该项目颁发的最高荣誉奖项，随后受邀留任担任内科总住院医师（Chief Medical Resident）。
- **专科与临床科研**：接受了长达 4 年的胃肠病学（Gastroenterology）专科临床与科研双轨训练。
- **当前科研角色**：本以为结束培训后不会再大规模发表论文，但目前他担任知名精准营养与健康科研机构 Zoe 的美国医学总监（US Medical Director），继续深度参与前沿的临床科研。
针对非医学专业观众对“胃肠病学家（Gastroenterologist）”这一拗口词汇的疑惑，Dr. Will 幽默而接地气地用一句话总结自己的本职工作：“我们就是专门负责研究‘肠子和屁股（guts and butts）’的专家。”
---
### [03:59](https://www.youtube.com/watch?v=qqabbfk9wV8&t=239s) 肠道微生物：被忽视的人体基石与“超级有机体”的诞生
在医学和大众健康领域，“肠道微生态”一词真正在公众舆论中爆炸式普及，主要集中在近两三年内。以往人们照镜子时感到身体不适、畏寒、腹胀或腹痛，传统医学与大众认知往往将其视为一个个孤立的症状，或者简单归结为“吃得好不好”这种黑匣子模型。而现代前沿研究揭开了这个黑匣子：所有食物与生活习惯的选择，最终都是通过对肠道微生物施加影响，进而系统性地重塑整个人体的底层生理机制。
所谓的“肠道微生物”，是指栖息在人体内微小却充满活力的生命形态。人类不仅皮肤表面覆盖着微生物，其最主要的聚集地位于消化道末端的结肠（大肠），那里密集寄宿着约 38 万亿个活体微生物。这个庞大的微生物群落以细菌为主，同时也包含真菌、寄生虫和病毒：
- **微生物的初相遇**：胎儿在母亲子宫内基本处于相对受保护的环境，直到羊水破裂的那一刻，婴儿才真正迎面接触外部微生物世界。
- **自然演化的第一道礼赠**：当婴儿顺着产道自然分娩时，会深度浸润在母体的微生物环境中。Dr. Will 将这比喻为大自然向新生儿发出的问候：“欢迎来到这个世界，来看看你终生的共生伙伴吧，它们将在此后一生中保护你、成就你的健康。”
- **数亿年的共同演化**：人类这个物种的演化历史仅有三四百万年，而微生物作为地球上最早出现的生命形式，其与生命的共同演化历程已超过十亿年。人体的免疫系统早在人类诞生前数亿年，就在与微生物的博弈和共生中奠定了雏形。
```mermaid
flowchart LR
accTitle: 婴儿与微生物的相识与共生建立流程
accDescr: 展示从母体子宫、破水到产道分娩时微生物接种的过程。
A["母体子宫环境<br/>(相对无菌/极少接触)"] --> B["羊水破裂<br/>(初次接触外界菌群)"]
B --> C["通过产道分娩<br/>(自然界微生物全面接种)"]
C --> D["定植大肠结肠<br/>(建立38万亿共生群落)"]
```
Dr. Will 强调，人类绝非一个孤立运作的单一有机体，而是由宿主细胞与数以十万亿计的微生物协同共存的“超级有机体（Superorganism）”。正如 1970 年代著名的“泡泡男孩”（由于重度免疫缺陷被迫生活在完全无菌的环境中）案例所揭示的，脱离了微生物的彻底无菌环境，对人类生理机能而言是灾难性的。在漫长的演化中，人类机体已将维系生命至关重要的任务完全托付给了微生物伙伴：它们不仅负责消化分解食物以输送生命能量，更在出生后前三年承担着严苛“训练”人类免疫系统的重任，直接决定了个体日后是否会发生过敏及自身免疫性疾病；同时，Zoe 的最新临床研究也已无可辩驳地证明，肠道菌群在调控餐后血糖水平和血脂代谢反应中发挥着决定性的核心作用。
### [09:19](https://www.youtube.com/watch?v=qqabbfk9wV8&t=559s) 肠道微生态对身心健康的全方位掌控
肠道微生物的影响力不仅限于肠胃本身，它还深刻地左右着人类的日常状态与整体健康：
* **大脑与精神状态**：情绪、日常精力水平、是否罹患抑郁症、认知功能、记忆力以及专注度，都受到这些微生物的直接调控。
* **内分泌与激素平衡**：在女性群体中，子宫内膜异位症（Endometriosis）与多囊卵巢综合征（PCOS）等疾病均已被证实与肠道微生态失调密切相关；在男性群体中，常被社会污名化且缺乏公开探讨的勃起功能障碍（ED），同样与肠道微生态存在紧密联系，对受此困扰的男性而言往往是头等大事。
从消化系统、免疫防御、新陈代谢，到激素调节、情绪状态乃至大脑健康，在消化科医生眼中，肠道微生态的运作机制正是审视整个人体健康的全局核心。
---
### [10:14](https://www.youtube.com/watch?v=qqabbfk9wV8&t=614s) 基因的微小差异与肠道菌群的巨大分野
人类之间的个体差异在肠道微生态上表现得尤为剧烈。若对比任意两个人的基因密码，彼此之间的相似度高达 99.99%，正是那不到 0.01% 的基因差异构成了生物学意义上的个体特征。然而，寄居在人体内的 38 万亿个微生物却呈现出完全不同的图景：
* **同卵双胞胎的对照**：即便是共享 100% 相同 DNA、同一位母亲、相同的童年生活环境和饮食习惯的同卵双胞胎，研究显示他们体内重合的微生物种类也仅约 25%，存在超过 75% 的巨大差异。
* **普通人之间的差异**：对于没有血缘关系的普通人而言，即便日常饮食结构非常接近，彼此体内的微生物构成依旧是“差异远大于共性”。
```mermaid
flowchart TD
accTitle: 人类基因组相似度与肠道微生物相似度对比
accDescr: 对比人类在DNA基因层面高达99.99%的相似度，与即使是同卵双胞胎也仅共享约25%肠道菌群的巨大差异。
subgraph GENETICS["人类遗传基因 (DNA)"]
G1["两个人之间的基因序列"]
G2["99.99% 完全相同"]
G1 --> G2
end
subgraph MICROBIOME["肠道微生态 (38万亿微生物)"]
M1["同卵双胞胎 (同DNA/同环境)"]
M2["仅 ~25% 微生物相同"]
M3["> 75% 存在显著差异"]
M1 --> M2
M1 --> M3
end
```
---
### [11:48](https://www.youtube.com/watch?v=qqabbfk9wV8&t=708s) 临床病历背后的“隐形共性”：慢性疾病与肠道损伤
面对“有多少疾病可归因于肠道微生态”的问题，虽然很难用单一全局百分比进行概括，但从消化科临床实践来看，几乎每一位前来就诊的患者都伴有肠道微生态受损：
* 常见的肠胃疾病：肠易激综合征（IBS）、克罗恩病（Crohn's Disease）、溃疡性结肠炎、乳糜泻（Celiac Disease）、胃食管反流等。
* 伴随出现的系统性慢性病：医生在门外翻阅病历时，除了肠易激综合征等主诉症状外，病史中往往还列有一长串由肠道微生态受损驱动的伴发疾病——高脂血症、高血压、2型糖尿病、重度抑郁症病史，以及各类自身免疫性疾病。
临床上往往不需要专门的粪便检测，单凭这些系统性疾病的交织呈现，就足以判定患者的肠道屏障与微生态早已遭受破坏。
---
### [13:35](https://www.youtube.com/watch?v=qqabbfk9wV8&t=815s) 70% 的免疫系统与单层细胞屏障
大众通常认为骨髓是免疫系统的大本营，但实际上骨髓只是免疫细胞诞生的“产房”。免疫细胞生成后，会离开骨髓并在**肠壁组织**中定居——人体有高达 70% 的免疫系统驻扎在肠道。
从进化生物学角度来看，肠道是人体最脆弱的界面：
* 皮肤是一堵厚实的物理阻隔墙，而肠道则是一个每天进行主动抉择的门户：哪些营养该被吸收进入体内，哪些潜在有害物必须被排斥在外。
* **单层上皮细胞屏障（Epithelial Layer）**：担当这一隔离重任的，仅仅是厚度只有单个细胞的上皮层，各细胞之间依靠微小的“紧密连接”（Tight Junctions）紧密黏合。
* 单层屏障的一侧是人体 70% 的免疫防御大军，另一侧则是 38 万亿个微生物。
一旦紧密连接遭到破坏形成“肠漏”，肠腔内的有害物质和内毒素便会渗透进血液循环，引发全身性免疫应急反应。在 20 世纪与 21 世纪爆发式增长的**慢性全身炎症**，本质上正是这道单层防线持续破损、迫使免疫系统长期处于高度紧绷状态的直接后果。
```mermaid
flowchart LR
accTitle: 肠道上皮单层细胞屏障结构
accDescr: 展现肠腔内38万亿微生物与体内70%免疫系统之间，仅隔着一层由紧密连接维持的单层上皮细胞。
subgraph INTESTINE_LUMEN["肠腔内部"]
M["38 万亿肠道微生物<br/>与未消化食物成分"]
end
subgraph EPITHELIAL_BARRIER["肠屏障 (仅单层细胞)"]
T["单层上皮细胞<br/>依靠紧密连接紧扣"]
end
subgraph BODY_SYSTEM["人体内部 / 循环系统"]
IMM["70% 的人体免疫细胞<br/>驻扎于肠壁"]
B["血液循环系统"]
end
M <-->|"屏障受损则渗入"| T
T <-->|"防御隔离"| IMM
IMM --> B
```
---
### [15:57](https://www.youtube.com/watch?v=qqabbfk9wV8&t=957s) 细胞的极速翻新与微生物的指数级繁殖
维持这道防线稳固的关键正在于肠道菌群本身，它们是肠道物理屏障的日常“修补工”：
* **肠壁细胞更替周期**：肠道上皮屏障并非终身不变，人体每 3 到 4 天就会将其彻底更新重造一遍；健康的菌群是引导并支持这一层新生屏障健全闭合的前提。
* **细菌的极速增殖能力**：肠壁上皮细胞是宿主细胞，每数天更新一次；而肠道内的细菌则大约每 20 分钟便能分裂一次。如果肠道内最初只有一个细菌，在持续喂养的条件下，仅仅 24 小时后它就能增殖分化出至少 1,000 个后代。这也意味着，人体的每一次进食选择都会被微生物的极速裂变急剧放大。
---
### [17:41](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1061s) 食物即药物：36 吨食物对身体的终身塑造
人们习惯于把食物视为消除饥饿的能量来源，把生病时服用的几毫克药片当作改变生理机制的“药物”。然而，将摄入规模拉长到整个人生尺度时，这种认知便会被彻底颠覆：
* 人均每天消耗约 1.3 公斤食物。
* 每年累计摄入约 475 公斤食物。
* 人类一生中摄入的食物总量高达约 **36,300 公斤（逾 36 吨）**。
相比于微克或毫克级的药丸，这数十吨日复一日穿过肠道、喂养数十万亿微生物的食物，才是时刻重塑人体生理机能与肠道健康的真正“药物”。这一认知正对应了 2014 年发表在《自然》（Nature）期刊上一项彻底改变医学界视野的里程碑式研究。
### [18:49](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1129s) 杜克大学突破性研究：饮食在24小时内重塑肠道菌群
威尔·布尔谢维奇（Dr. Will Bulsiewicz）博士回顾了近十年前发表在顶级科学期刊《自然》（Nature）上的一篇里程碑式论文。该研究由杜克大学的劳伦斯·戴维（Lawrence David，转录文本中误作 Warren David）主导。在当时，科学界虽然已知饮食会改变小鼠的肠道菌群，但人类与小鼠存在本质差异，食物是否能迅速改变人体的微生物群仍是一个未知数。为了验证这一点，研究人员将受试者置于完全截然相反的饮食模式中：一组采用100%全植物性饮食，另一组则采用100%纯动物性饮食。这项实验仅仅持续了5天，却带来了震撼的科学发现：人类今天所做的饮食选择，在短短24小时之内就会对肠道微生物组产生显著影响。
布尔谢维奇博士强调，这一发现传达出的核心理念是“肠道具有极强的宽容度”（the gut is forgiving）。肠道固然经不起无休止的折腾，但也绝不存在非黑即白的严苛禁忌。人们不必彻底把某些食物完全排除在餐桌之外，关键在于建立一种倾斜机制——即大幅提高优质健康食物的摄入比例。只要倾斜天平、多吃高质量食物，就能有效扶持并激活体内那些有益的微生物。
- **实验设计**：对比100%纯植物性饮食与100%纯动物性饮食，为期仅5天。
- **核心结论**：饮食模式改变后，肠道菌群在24小时内便开始发生显著重塑。
---
### [20:15](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1215s) 喂养体内的“生命”：每周30种植物的黄金法则
当史蒂文询问食物与微生物的关系是否就像“浇灌特定植物”一样时，布尔谢维奇博士给出了形象的解释：肠道内的微生物和人类一样是有生命的实体，它们同样会感到饥饿。微生物原本可以栖息在土壤中或植物表面，但它们最终选择定居在人类的大肠里，原因就在于人类能够外出搜寻食物并直接将营养输送到它们嘴边。人类吞下的每一口食物都会与这些微生物相遇并成为它们的能量来源。然而，不同的微生物有着截然不同的“偏好”——有的微生物专爱吃羽衣甘蓝，有的则偏爱糖分；人类每一次的饮食选择，本质上都是在决定让哪个菌群饱餐一顿、茁壮成长。
布尔谢维奇博士在其著作《纤维驱动》（Fiber Fueled）中倡导的理念，与蒂姆·斯佩克特（Tim Spector）教授在“美国肠道计划”（American Gut Project，该研究也涵盖了至关重要的英国肠道计划部分）中得出的科学结论高度契合：维持肠道健康的终极法宝在于植物多样性。该研究所确定的黄金指标是“每周摄入30种不同的植物”。布尔谢维奇博士解释称，30并不是一个绝对的非黑即白门槛，并非吃29种就不及格、吃到30种就奇迹发生，健康是一个连续的谱系。这里的植物概念极为宽泛，涵盖了水果、蔬菜、全谷物、种子、坚果以及豆类，绝非单调地嚼羽衣甘蓝。
面对当下欧美现代人群普遍每周仅摄入10至15种植物的现状，布尔谢维奇博士倡导“循序渐进”的健康管理策略。他坦言自己十年前的饮食丰富度甚至还达不到10种；如果让一个平时只吃10种植物的人立即强行跃升至30种，这种剧变往往极其困难且难以长期坚持。更务实的做法是先从10种稳步提升到15种，每一次微小的进步都值得庆贺。
```mermaid
flowchart TD
accTitle: 植物多样性对肠道微生态的滋养路径
accDescr: 展示摄入多种植物后如何分化滋养肠道不同菌群并产出健康收益的流程图
subgraph INTAKE ["植物多样性摄入（目标：每周30种）"]
P1["水果与蔬菜"]
P2["全谷物与豆类"]
P3["坚果与种子"]
end
subgraph COLON ["结肠环境：精准喂养"]
F1["专性纤维分解菌"]
F2["拟杆菌与双歧杆菌等"]
end
subgraph OUTCOME ["健康正向循环"]
H1["微生态多样性显著提升"]
H2["生成有益代谢物，赋能全身"]
end
P1 & P2 & P3 --> F1 & F2
F1 & F2 --> H1 --> H2
```
---
### [23:28](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1408s) “亚马逊雨林”对决“街角小公园”：从日常饮食中找回多样性
史蒂文分享了自己与伴侣进行 Zoe 肠道检测后的鲜明对比：测试结果显示他的肠道微生态极其单一，而他伴侣的菌群多样性却异常丰富。史蒂文幽默地调侃道，伴侣在餐厅总是热衷于尝试新奇菜品，家里的冰箱上层更是塞满了芝麻酱（Tahini）和各类发酵食品，吃起东西来“就像一只不知疲倦的兔子”；相比之下，史蒂文自己饮食极度单一且固定，任何跟他吃过三次饭的人都能闭着眼睛替他点菜。检测报告出来的结果令人大开眼界——伴侣的肠道菌群繁茂得宛如“亚马逊雨林”，而史蒂文的肠道却凄凉得宛如“街角尽头的小小绿地”。
布尔谢维奇博士对此表示，绝大多数现代人都和史蒂文一样倾向于停留在饮食舒适区，但科学的魅力正在于揭开过去的“黑箱”：我们如今确切明白食物直接决定微生物，而微生物又反过来主宰人体的健康。意识到每一顿饭都是一次为肠道增添多样性的契机，这本身就是一种巨大的动力。他随即敏锐地指出，史蒂文伴侣饮食习惯中的另一个制胜法宝正是西方现代饮食中几乎失传的技艺——发酵食品。斯坦福大学进行的一项严谨的随机对照试验（RCT）证实，让此前不吃发酵食品的人群在日常饮食中加入发酵食物，仅在8周后，其肠道微生物的多样性便迎来了飞跃。只要引入发酵饮食，即便是“街角小公园”般的萧条肠道，也完全有希望演变成生机盎然的“热带雨林”。
---
### [25:39](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1539s) 驯化微生物的魔法：发酵食品与“后生元”超级力量
布尔谢维奇博士深入浅出地拆解了发酵的科学本质。地球上的所有生命都有自己的微生物组，例如一颗刚从果盘里拿起的普通新鲜苹果，表面与内部就共生着大约1亿个微生物，它们陪伴苹果从花朵成长为果实。当食物放置变质时，正是微生物在履行大自然的降解循环；食物会腐坏其实令人安心，反倒是“永远不坏的食物”才该引起警惕。而人类发明的发酵技术，本质上就是扮演“魔法师”的角色，主动介入并掌控这一生命循环过程——通过营造特定环境，赋予特定益生菌压倒性优势，从而保护食物不至于腐败变质，并使其发生神奇的营养蜕变。
为了说明发酵的操作与魅力，布尔谢维奇博士以自制德国酸菜（Sauerkraut）为例：只需将农贸市场买来的普通卷心菜切碎，塞入玻璃密封罐中，加入天然海盐水溶液，在阴凉处静置一周即可。由此诞生的酸菜完全不同于超市货架上那些软烂难吃的工业罐头，它带有鲜明清脆的微酸、微苦与丰富风味。在发酵过程中，细菌与酵母菌大快朵颐并成倍繁殖，将这罐普通的卷心菜转化成了集三重益处为一体的真正“超级食物”：
- **益生菌（Probiotics）**：发酵过程中微生物大量繁殖，赋予食物极高密度的活性有益活菌。
- **益生元（Prebiotics）**：食物在微生物作用下结构被转化解锁，暴露出专门滋养人体内有益菌的膳食纤维等关键养分。
- **后生元（Postbiotics）**：微生物在发酵代谢过程中分泌释放出的全新化学活性物质，进入人体后对机体健康产生强效的正面调节作用。
### [28:37](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1717s) 发酵食物的真相与“三大生元”（益生元、益生菌、后生元）辨析
威廉·布尔谢维奇（Dr. Will Bulsiewicz）由酸菜（Sauerkraut）和泡菜（Kimchi）谈起，纠正了大众对腌黄瓜（Pickles）的普遍误解：传统的腌黄瓜绝不是把黄瓜扔进醋里那么简单，虽然醋本身也是发酵的产物，但真正的腌制工艺根本不需要额外加醋。地道的做法是保留黄瓜表皮，利用表皮天然附着的微生物，将它们浸泡在盐水溶液中，加入莳萝、大蒜和黑胡椒粒，让微生物在几天内自然发酵成酸爽的腌黄瓜。
随后，史蒂芬·巴特利特（Steven Bartlett）希望梳理清楚经常被混淆的“三大生元”概念。布尔谢维奇对此进行了严谨的界定与修正：
- **益生元（Prebiotics）**：微生物的食物。但关键的判定前提是它必须对人体产生经临床证明的有益效果。例如糖能被微生物利用，但它绝不是益生元。
- **益生菌（Probiotics）**：活的微生物本身。大多数人最熟悉的形态是胶囊制剂，能够被称为益生菌，同样是因为特定菌株或酵母在临床研究中被证实对人体健康有益。
- **后生元（Postbiotics）**：非活体化合物，即活的微生物代谢消耗益生元后制造出的活性物质。
面对史蒂芬半开玩笑地发问“我难道不能直接买一罐后生元饮料喝下去吗”，布尔谢维奇指出，市场上确实开始涌现此类后生元补充剂，但他与保健品行业从业者沟通时明确强调：绝不能理所当然地认为吃药片或喝饮料能完全替代高纤维天然饮食带来的复杂生理效益。
```mermaid
flowchart LR
accTitle: 三大生元的作用链条
accDescr: 展示益生元、益生菌与后生元之间的转化关系及其最终靶向的人体系统
A["益生元 (Prebiotics)<br/>膳食纤维与抗性淀粉"] -->|喂养| B["益生菌 (Probiotics)<br/>肠道活体微生物"]
B -->|代谢产出| C["后生元 (Postbiotics)<br/>短链脂肪酸 SCFAs 等"]
subgraph S["人体健康系统"]
C --> D["肠道屏障保护"]
C --> E["免疫调节与抗炎"]
C --> F["代谢与大脑轴调控"]
end
```
---
### [31:19](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1879s) 后生元与短链脂肪酸（SCFA）：筑牢肠道屏障与全身修复
布尔谢维奇解释道，整个肠道菌群之所以对健康至关重要，其核心机制就在于它们能够源源不断地生成各种有益的后生元。其中最典型的代表就是**短链脂肪酸（SCFAs）**——包括丁酸（Butyrate）、乙酸（Acetate）和丙酸（Propionate）。这些化合物是肠道微生物在发酵分解人体无法自行消化的膳食纤维或抗性淀粉时产生的；如果一个人体内处于完全无菌的状态，就根本无法生成这些物质。
短链脂肪酸是维系人体防御体系的基石。布尔谢维奇此前提到肠道屏障是保护人体免疫系统的关键防线，而肠道微生物就是这座防线的“管家”，它们筑墙的“水泥与砖块”正是短链脂肪酸。增加短链脂肪酸的生成，能加固肠壁完整性、显著降低全身性慢性炎症。
除了筑牢肠道局部防线，这些后生元还会直接进入血液循环系统并流经全身：
- **免疫与代谢调控**：直接与免疫细胞及代谢器官受体结合，调整防御机制与能量消耗。
- **穿透血脑屏障**：短链脂肪酸具备跨越血脑屏障的能力，可直接进入大脑中枢，对神经系统产生调节与滋养作用。
这揭示了膳食纤维对健康极为关键的底层生物学机制：人体从高纤维饮食中获得的广泛益处，本质上正是肠道微生物吞噬纤维后释放出短链脂肪酸所带来的全身性修复效应。
---
### [33:10](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1990s) 肠道与新陈代谢的深层关联：PREDICT 1 研究
在谈到新陈代谢（Metabolism）时，史蒂芬提到大众常将代谢简单理解为“消化食物的速度”——代谢快的人往往吃不胖，代谢慢的人则体重容易增加。布尔谢维奇纠正并深化了这一认知：新陈代谢实质上是人体处理能量货币的系统引擎。肠道菌群与这一引擎之间存在着精密而复杂的纽带。
依托于佐伊健康（Zoe）开展的 **PREDICT 1 研究**，科学家们深入探究了进食后人体血糖与血脂波动的预测因素。研究表明，虽然每个人的血糖波动和餐后血脂反应存在极其显著的个体差异，但肠道微生物群在决定这两项关键代谢指标上均扮演着不可替代的决定性角色。只要掌握了一个人的肠道菌群构成特征，科学家便能有效预测并解释其血糖或血脂调节异常的原因。
从细胞与生化机制来看，短链脂肪酸在代谢调控中再次发挥了核心作用：
- **激活细胞受体**：增强外周组织对胰岛素的敏感性。
- **调节脂肪去向**：抑制体内脂肪合成储存，同时显著增强脂肪氧化分解（燃脂）。
- **优化多维代谢指标**：从餐后血糖反应、餐后血脂水平、总胆固醇控制，到深层的内脏脂肪（Visceral Adiposity，即腹部器官周围脂肪的堆积），肠道菌群及其产生的短链脂肪酸都是幕后不可或缺的调节中枢。
---
### [35:26](https://www.youtube.com/watch?v=qqabbfk9wV8&t=2126s) 便便中的健康密码与“蓝色便便”肠道转运时间测试
当史蒂芬提到布尔谢维奇书中“**大便中 60% 的成分其实是细菌**”这一数据时，直呼颠覆认知。布尔谢维奇顺势呼吁社会打破对排泄物的病态耻感与禁忌。大众往往羞于在便后回头观察马桶，然而正如心脏科医生通过把脉和听诊心跳来评估基础心血管状况一样，胃肠科医生了解患者基础全身健康的第一步，正是询问排便形态与规律。粪便不仅仅是未消化的食物残渣，其超过半数的微生物属性使其成为洞察肠道生态的直观“活体晴雨表”。
为了将这一机制转化为普通人触手可及的健康工具，Zoe 团队设计并开展了著名的**“蓝色便便”（Blue Poo）研究**，该论文发表在欧洲胃肠病学顶尖期刊《Gut》上。研究者让受试者食用加入特殊蓝色食用色素的蓝色松饼，并精准记录从松饼“入口”到蓝色色素首次“出现在马桶中”的时间跨度，即**肠道转运时间（Gut Transit Time）**。这项简单测试能够直接映射出个体的肠道微生物多样性、心血管疾病风险乃至内脏脂肪含量。
- **快速转运（低于 14 小时）**：食物在肠道内停留过短，反映肠道蠕动异常亢进或吸收障碍。
- **正常均值（约 24 小时左右）**：绝大多数健康人的转运时间稳定在此区间。
- **迟缓转运（超过 58 小时）**：极度缓慢的肠道转运，通常提示肠道生态失调及代谢风险上升。
布尔谢维奇强调，选择经过临床验证的蓝色色素而非甜菜根等天然染色食物，是为了保证实验计时的科学性与可复现性；无论是代谢状态、免疫功能还是内脏脂肪堆积，都可以通过便便形态及肠道转运时间这一基础生理体征找到清晰的线索。
### [38:39](https://www.youtube.com/watch?v=qqabbfk9wV8&t=2319s) 肠道转运时间与膳食纤维的双向调节作用
通过蓝色松饼测试观察排便显色时间，通常在食用后 24 小时或 48 小时左右看到蓝色粪便排出，这两个时间峰值都被视为正常范围。若按转运时间将人群细分为四组——极速（少于 14 小时）、极慢（超过 58 小时）以及处于 24 和 48 小时两个峰值的群体，会发现每一组人的肠道微生物组和菌群多样性都截然不同。饮食与这些数据存在极强的相关性：高纤维饮食者的转运时间都稳稳落在中间的“正常”区间，而低纤维饮食者则散落在过快或过慢的两个极端。
膳食纤维展现出一种令人惊叹的双向调节特性：无论是腹泻还是便秘，世界上唯一能同时改善这两类问题的物质就是膳食纤维。它能重构粪便形态，使其恢复到健康的适中状态。理想情况下，最健康的状态是每天排便一次左右，即肠道转运时间控制在 24 小时或更短。不过，若某些人需要 48 小时才排出蓝色，并不能直接断定其身体不健康。使用蓝色松饼自测转运时间，是一个成本极低、人人都能在家尝试的简易健康评估工具。
```mermaid
flowchart TD
accTitle: 肠道转运时间与膳食纤维关系图
accDescr: 展示高纤维与低纤维饮食如何影响肠道转运时间及排便状态
subgraph Fast["极端过快 (<14小时)"]
A["腹泻 / 稀便"]
end
subgraph Optimal["理想黄金区间 (24-48小时)"]
B["高纤维摄入者"]
C["每日排便一次 · 菌群多样性丰富"]
B --> C
end
subgraph Slow["极端过慢 (>58小时)"]
D["便秘 / 慢性干结"]
end
LowFiber["低纤维饮食群体"] -.-> A
LowFiber -.-> D
FiberFix["增加膳食纤维 (双向调节)"] -->|固化稀便| Optimal
FiberFix -->|软化通便| Optimal
```
### [40:06](https://www.youtube.com/watch?v=qqabbfk9wV8&t=2406s) 肠道菌群与纤维消化：“慢起步，稳增加”
当人们每天排便三到四次以上，或者长期饱受慢性便秘困扰时，其底层往往都指向同一个根源——膳食纤维匮乏。然而，增加纤维摄入并不像表面看起来那么轻松。对于长期低纤维饮食的人而言，突然大量摄入纤维会极其难受，甚至让人腹痛到“整个人蜷缩起来”（folds them over）。Dr. Will 分享道，十年前他也曾身处同样的境地，当时如果吃下一碗放满豆类的浓汤辣椒（chili），肚子就会翻江倒海、痛苦不堪，以至于本能地避开这类食物。
人类在消化纤维方面完全依赖肠道微生物。人体自身并不分泌分解膳食纤维的消化酶，这项繁重的工作全由肠道微生物组包揽。如果一个人的肠道菌群受损，且常年不吃纤维，肠道菌群就根本没有消化纤维的实战能力——“微生物需要练习，只有通过实践才能掌握这项技能”。Dr. Will 建议想要增加纤维摄入的人务必遵循“起步要低，增量要慢”（start low and go slow）的黄金法则，用数周甚至数月的时间微量渐进，给肠道微生物足够的缓冲期去自我调整与繁殖。
- 人体自身无法产生分解膳食纤维的酶，完全依赖结肠内的共生微生物完成发酵与代谢。
- 长期缺乏膳食纤维会导致相关功能菌群萎缩，骤然高纤维饮食会引发胀气、腹绞痛等消化道应激反应。
- 渐进式调整策略以“周”或“月”为单位缓慢增量，为菌群重构提供适应空间。
### [41:51](https://www.youtube.com/watch?v=qqabbfk9wV8&t=2511s) 粪菌移植的奇迹与“超级供体”之谜
既然受损的肠道菌群难以直接分解高纤维，Steven 顺势提出了一个看似大胆却直击本质的问题：能否直接摄入健康人的粪便，通过粪菌移植（Fecal Microbiota Transplantation, FMT）快速修复肠道？Dr. Will 证实这项医学技术早已落地，在临床上治疗艰难梭菌（*C. diff*）感染已有十余年历史，且治愈效果极其惊人。然而，当科学家试图将粪菌移植推广至溃疡性结肠炎等炎症性肠病（IBD）时，整体研究的成功率却并不如艰难梭菌那样立竿见影。
在一项关于溃疡性结肠炎的小型临床试验中，研究人员观察到少数患者在接受粪便移植后病情得到了彻底缓解（remission）。深入追踪后发现，所有实现临床缓解的患者竟然接受的是“同一位供体”的样本。这一关键线索表明，自然界中可能存在针对特定疾病的“超级供体”：
- 肠道微生物组与宿主疾病存在复杂的特异性匹配机制。
- 某种特定疾病的痊愈钥匙，可能正藏在某个甚至不知道自己是供体、完全健康的人的肠道中。
- 未来的精准医疗需要通过更大型的临床研究，解开“何种供体菌群能治愈何种特定疾病”的匹配密码。
### [43:57](https://www.youtube.com/watch?v=qqabbfk9wV8&t=2637s) 胶囊化技术的兴起与微生物大灭绝危机
谈及粪菌移植的操作方式，传统的经典做法是通过结肠镜检查（colonoscopy），在患者处于全麻入睡状态下，经由肠镜管道将悬浊液体释放到肠道深处。但频繁进行肠镜操作无论从成本还是身体耐受度上都无法长期维系。如今前沿科技已开发出冷冻干燥（冻干，lyophilize）技术，将筛选纯化后的健康粪便菌群制成口服胶囊。Steven 幽默地联想到自己曾不小心咬破高浓度 Omega-3 鱼油胶囊的噩梦经历，笑称粪便胶囊若是破裂后果不堪设想；同时打趣道，如果有公司能实现“每天一粒超级粪便胶囊”的日常调理，自己真想去当那家公司的 CEO。
这项技术的核心本质是打造超越普通单菌株益生菌的“超级益生菌”（super probiotic），直接完整重构宿主生态系统。Dr. Will 强调，这在未来绝不会作为普通保健品流通，而必然受到与处方药同等级别的严格医学监管。更令人警惕的是，微生物学家当前正对全球范围内的“微生物大灭绝”（microbial extinction event）深感忧虑：
- 现代西方工业化生活方式导致人体肠道微生物丰富度断崖式下跌。
- 相比非洲生活在原始自然环境中的传统部落人群，现代西方人体内的微生物种类整整少了一半。
- 科研团队正在紧急建立生物样本库，采集并冷冻保存非洲原始部落人群的粪便样本，以防未来现代人彻底丧失关键共生菌株时，这些冷冻样本能成为人类重塑肠道生态的最后诺亚方舟。
谈话尾声，两人展开了极具讽刺幽默意味的畅想：随着健康粪便的战略价值水涨船高，那些拥有完美肠道菌群、每天定时顺畅排便的人，其排泄物或许会变得价值连城。Dr. Will 打趣称“我的身价正在暴涨”，Steven 则调侃道在未来的后 AI 时代，人类无所事事，也许健康粪便就会取代黄金成为硬通货。这一设想虽然荒诞诡异，却以最深刻的方式映照出人类正在重新审视肠道微生物对物种存续的非凡价值。
### [48:18](https://www.youtube.com/watch?v=qqabbfk9wV8&t=2898s) 便便的阶层与古老饮食的隐秘财富
在过去被视为毫无价值、令人厌恶的排泄物，如今摇身一变成了医院里对抗顽固重度感染的尖端疗法，甚至是生命科学的最前沿。史蒂芬·巴特利特（Steven Bartlett）打趣道，未来社会的阶级划分可能会彻底改写：顶级上流阶层不再由财富定义，而是由拥有最优质便便的人组成；而低阶层的人则因肠道微生物单一匮乏、便便毫无利用价值，甚至卖不出一分钱。
威尔·布尔谢维奇博士（Dr Will Bulsiewicz）顺着这个风趣的设想指出，现实中往往恰恰相反：许多欠发达地区的居民经济拮据，吃的都是最朴素的基础食物——全谷物和豆类（如最经典的米饭配豆子）。然而，正是这些常被西方忽视的平民饮食，富含膳食纤维、抗性淀粉和多酚类物质，构成了顶级的益生元组合。研究一再证明，豆类摄入较多的人群寿命更长、患病率更低。那些廉价却正宗的原生态食材，才是肠道微生物最渴望的滋养源。
史蒂芬随即幽默地调侃，西方人过去曾乘船远征非洲掠夺黄金和钻石，如今这批懒惰的西方殖民者后裔，恐怕又要扬帆出海去抢夺原生态人群的优质“便便”了。布尔谢维奇博士笑着回应，在考古和古生物学领域，甚至早已有人为争夺史前化石便便的科研控制权而大打出手。这正如电影《侏罗纪公园》（Jurassic Park）开篇通过针管从琥珀中的蚊子提取远古 DNA 一样，科学家们同样渴望提取史前人类便便中的微生物 DNA，以此破译古代人类强大的肠道密码。
- **被忽视的超级食物（豆类）**：富含膳食纤维、抗性淀粉与多酚，是最具性价比的天然益生元组合。
- **健康悖论**：欠发达地区因食用糙米和豆类等粗粮，其肠道微生物的多样性与韧性往往远胜于食用深加工食品的富裕发达国家人群。
---
### [50:16](https://www.youtube.com/watch?v=qqabbfk9wV8&t=3016s) 粪菌移植实验：疾病与体质的“生物学拷贝”
肠道微生物如何真正主导机体健康？答案很大程度上来自严谨的小鼠粪菌移植（FMT）模型。布尔谢维奇博士详细介绍了一项极具震撼力的经典临床研究：研究人员挑选了拥有完全相同基因组的同卵双胞胎，其中一位肥胖，另一位纤瘦。当研究人员将这对双胞胎的肠道菌群分别移植给小鼠后，即便在完全相同的饲养环境、喂食一模一样的食物和精准等量卡路里（Calories）的情况下，两只小鼠却复制了供体的体型——接收肥胖者菌群的小鼠迅速发胖，而接收纤瘦者菌群的小鼠则保持苗条。
布尔谢维奇博士形象地将这种代谢差异比作游泳：“移植了肥胖菌群的小鼠，其生理机能仿佛在逆流而上，肠道菌群会极度高效地榨取吸收摄入的所有热量；而移植了瘦人菌群的小鼠则如同顺水行舟，消耗同样的热量却完全不长肉。”除了体重，科学家还证实糖尿病、溃疡性结肠炎，甚至是情绪表型（如焦虑、抑郁、创伤后应激障碍 PTSD）均能通过人源粪便移植在小鼠体内精准复刻。尽管人体系统的复杂性意味着目前无法单凭粪菌移植彻底根治人类所有的代谢和精神疾病，但这些动物实验从因果层面铁证了肠道菌群的核心主导地位。
```mermaid
flowchart TD
accTitle: 粪菌移植代谢表型传递机制
accDescr: 展示同卵双胞胎不同肠道菌群移植给小鼠后引发的不同代谢与体型结果
subgraph Donors["同卵双胞胎（基因完全相同）"]
D1["肥胖双胞胎<br/>高热量吸收型菌群"]
D2["纤瘦双胞胎<br/>高短链脂肪酸产出型菌群"]
end
subgraph Transplant["无菌小鼠粪菌移植（FMT）"]
M1["接收肥胖菌群小鼠"]
M2["接收瘦人菌群小鼠"]
end
subgraph Outcome["等热量与等成分饮食喂养"]
R1["逆流代谢模式<br/>强力吸收所有热量<br/>开启脂肪储存 → 显著发胖"]
R2["顺流代谢模式<br/>产生丰沛短链脂肪酸<br/>激活产热与排泄 → 维持苗条"]
end
D1 --> M1 --> R1
D2 --> M2 --> R2
```
- **糖尿病表型转移与改善**：人体临床试验表明，将非糖尿病健康供体的粪便移植给糖尿病患者，可直接显著改善其血糖指标。
- **免疫与肠炎**：将人类溃疡性结肠炎患者的粪便移植给小鼠，受体小鼠会同样患上溃疡性结肠炎。
- **心理神经表型传递**：人类焦虑、抑郁、PTSD 等神经心理异常表型，可通过肠道菌群成功跨物种移植给啮齿动物。
---
### [53:39](https://www.youtube.com/watch?v=qqabbfk9wV8&t=3219s) 短链脂肪酸、卡路里悖论与饥饿反弹的恶性循环
肠道微生物塑造体质的微观开关正是“后生元”（Postbiotics），其中最具代表性的是短链脂肪酸（SCFAs）。如果一个人的肠道菌群擅长分解纤维产生丰沛的短链脂肪酸，即便与他人进食完全相同的正餐，短链脂肪酸也会充当全身信号分子，全方位优化代谢：它能调节餐后血糖与血脂波动、提升胰岛素敏感性，并关闭脂肪储存开关、开启线粒体脂肪燃烧（产热作用）。此外，拥有健康肠道菌群的人，其排泄物中往往会排出更多未被吸收的多余热量。这彻底击穿了简单粗暴的“卡路里进出平衡说”（Calories in, calories out, CICO）。
面对患者“只要把披萨摄入量减半、控制总卡路里就能健康减肥”的困惑，布尔谢维奇博士直言这是极具破坏性的误区。虽然纯粹节食短期内会减轻体重，但身体会迅速启动代偿机制：基础代谢率断崖式下滑，食欲调控激素剧烈狂飙，迫使人陷入难以抗拒的暴饮暴食。随之而来的便是惨烈的“溜溜球式反弹”（Yo-yo effect），甚至反弹到比减重前更高的体重水平。更可怕的是，节食流失的体重中包含大量宝贵的肌肉组织，而反弹回来的却几乎全是不健康的纯脂肪，最终落得比减重前更加虚弱病态的结局。
博士给出的真正解药是告别受难式的限制饮食，转而拥抱以高益生元为核心的高品质饮食——让人们能够不受限制地尽情吃到饱腹，同时轻松达成理想体重。当前风靡全球的降糖减重药物诺和泰（Ozempic）与 Wegovy（主要活性成分为司美格鲁肽 Semaglutide）本质上是 GLP-1（胰高血糖素样肽-1）受体激动剂。GLP-1 是人体肠道天然产生的关键饱腹激素，而进食富含益生元的高纤维食物正是自主激活内源性 GLP-1 分泌、唤醒自然饱腹感的最佳天然路径。
- **短链脂肪酸（SCFAs）的全身调节靶点**：
- 提升外周组织胰岛素敏感性，平抑餐后血糖峰值；
- 抑制脂肪细胞的甘油三酯储存，激活机体产热（Thermogenesis）与脂肪氧化；
- 促使部分多余能量随粪便排出体外。
- **单纯节食（CICO）的三重危害**：
- **代谢降级**：机体启动饥荒代偿，大幅下调基础代谢率；
- **组织损失不可逆**：减重期间流失骨骼肌，反弹期间仅增长脂肪，严重恶化身体成分（Body composition）；
- **神经内分泌失衡**：饥饿激素剧烈反扑，极易诱发强迫性暴食与严重溜溜球反弹。
- **天然 GLP-1 激活途径**：无需依赖合成注射剂，高益生元饮食能持续刺激肠道 L 细胞分泌内源性 GLP-1，带来健康、可维系的自然饱腹感。
### [58:09](https://www.youtube.com/watch?v=qqabbfk9wV8&t=3489s) 超加工食品如何破坏饱腹感信号
当人体的自然饱腹感信号被正常激活时，摄入的热量自然就会减少。所谓饱腹感信号，本质上就是机体调控饥饿与停止进食的反馈机制。然而，现代人普遍面临的困境在于日常饮食充斥着超加工食品（ultra-processed food）。这类食物不仅让人食欲大开、欲罢不能，而且完全无法有效激活身体内在的饱腹信号。其直接后果便是摄入严重过量，导致餐后几个小时内整个人昏昏沉沉、感觉像“一堆垃圾”（feel like trash），其根本原因在于代谢系统被彻底打乱。
威尔·布尔谢维奇博士（Dr Will Bulsiewicz）指出，在超加工食品问世前的漫长岁月里，人类的进食模式其实非常自然：吃下一顿美味的食物，吃到饱便停下，饭后依然精力充沛，根本不需要补觉或靠能量饮料来支撑。这种传统进食方式依赖的是肠道激素的自然释放——例如胰高血糖素样肽-1（GLP-1）和酪酪肽（Peptide YY, PYY）。这些肠道激素是向身体发出“停止进食”指令的核心信号分子，能够在饱腹时自动踩下刹车。
```mermaid
flowchart TD
accTitle: 传统天然饮食与超加工饮食对饱腹感调控的机制对比
accDescr: 对比高纤维天然食物与超加工食品在胃肠道激活激素及代谢反应上的截然不同路径
subgraph NaturalPath["传统天然饮食机制"]
A["高纤维天然食物"] --> B["肠道微生物发酵产生短链脂肪酸"]
B --> C["释放饱腹激素: GLP-1 & PYY"]
C --> D["及时触发饱足感并自发停止进食"]
D --> E["能量充沛、代谢平衡"]
end
subgraph UltraProcessedPath["超加工饮食机制"]
F["超加工食品"] --> G["缺乏纤维与微量结构"]
G --> H["饱腹信号失灵 & 食欲失控"]
H --> I["过度进食"]
I --> J["代谢失衡、疲倦迟钝"]
end
```
---
### [59:25](https://www.youtube.com/watch?v=qqabbfk9wV8&t=3565s) 减重神药 Ozempic 的流行、风险与肠道盲区
史蒂文·巴特利特（Steven Bartlett）提到，现在全网都在为降糖减重药物 Ozempic（司美格鲁肽）疯狂，甚至连埃隆·马斯克（Elon Musk）等公众人物也公开表示曾使用过它。更值得注意的是，许多身材并不肥胖的人也将其视作能迅速让人产生饱腹感并减重的“超级神药”。
布尔谢维奇博士明确表示，对于确实有临床病理需求的人来说，这种药物的存在令人庆幸，但绝不意味着全世界都需要依赖它才能获得健康。Ozempic 存在非常确切且普遍的副作用，其中最显著的就是大面积的消化道不适症状。更关键的风险在于其长期影响的未知性：该药物问世时间尚短，缺乏长期随访数据，而患者一旦停药，体重往往会全盘反弹。这意味着使用者实际上是在做出长达数年乃至数十年的用药承诺。巴特利特敏锐地指出，通过直接注射或服用 Ozempic 来制造饱腹感，本质上是“跳过了建立健康肠道菌群的关键步骤”。
---
### [01:00:40](https://www.youtube.com/watch?v=qqabbfk9wV8&t=3640s) 膳食纤维的惊人力量与 Andrew Reynolds 研究
布尔谢维奇博士强调，社会普遍忽略了一个最核心的现实——膳食纤维严重匮乏。在大众眼里，纤维或许没有新奇药物那么“性感”，但它对机体运作至关重要。膳食纤维正是肠道微生物释放 GLP-1 和 PYY 等天然饱腹激素的原动力，而这一过程是通过微生物发酵产生的短链脂肪酸（Short-Chain Fatty Acids, SCFAs）实现的。
在新西兰学者安德鲁·雷诺兹（Andrew Reynolds）教授统揽全球所有相关数据的一项经典研究中，增加膳食纤维摄入给人体带来的益处被证实是全面且颠覆性的。摄入更多纤维不仅能带来自然的体重减轻，更能全面改善机体各项指标，其综合保护效应覆盖了全身主要器官系统：
- **体重与心血管改善**：促进体重下降，显著降低心肌梗死发作几率，减少心血管疾病死亡风险，降低中风概率，促使血压稳步下降，并能有效降低血液胆固醇。
- **血糖与癌症预防**：显著提高血糖调控能力，大幅降低被诊断出 2 型糖尿病的风险；同时显著降低多种癌症的确诊率以及因癌症导致的死亡率。
- **美英两国的现实鸿沟**：
- 约 95% 的美国人处于纤维缺乏状态；
- 美国成年女性日均纤维摄入量仅为 15 克，远低于推荐标准的至少 25 克；
- 美国成年男性日均纤维摄入量仅为 18 克，与推荐的 38 克相去甚远；
- 普通美国人仅有约 10% 的热量来源于富含纤维的植物性食物；若能将这一比例提升至 30% 或 50%，整个人群的健康状况将迎来天翻地覆的改变。
---
### [01:03:25](https://www.youtube.com/watch?v=qqabbfk9wV8&t=3805s) 走捷径的隐性代价：治标掩盖还是根除病因？
巴特利特分享了自己与身旁朋友的交谈经历。许多人热衷于使用 Modafinil（莫达非尼）、Ozempic 等各种改善表现或控制体重的药物，并坚称这些药“没有任何副作用”。巴特利特认为，除去那些因心血管疾病或严重糖尿病而真正需要药物救命的患者，大部分人使用这些药物纯粹出于虚荣或急功近利，本质上属于一种“作弊”，而“生活中的每一种捷径往往都标好了代价”。
布尔谢维奇博士对此非常赞同，称巴特利特的思考方式已经具备了医生的“风险与收益权衡（risk versus benefit）”思维。任何药物都伴随着潜在风险，而现代医学最大的痛点在于，总是等到非开处方不可的时候才介入治疗，却很少在病变早期通过调整生活方式彻底切断患病根源。
对于“走捷径往往更轻松”的现实，布尔谢维奇博士分析指出，捷径的直接收益显而易见，但长期成本却往往隐蔽不显：
1. **掩盖表象 vs 解决根因**：以 2 型糖尿病为例，降糖药可以迅速压低血糖，但这如同在问题上方“盖上了一层床单”（putting a sheet over the problem），并没有真正治好糖尿病。
2. **2 型糖尿病的高度可逆性**：大多数成年后获得的 2 型糖尿病其实具有极高的可逆性。在必要时使用药物控制固然正确，但健康管理的核心必须是瞄准病根（root cause），通过饮食和生活习惯的彻底重塑摆脱对药物的终身依赖。
3. **可持续性与意志力之辩**：巴特利特提出改变饮食习惯往往需要强大的自律、意志力与动力；布尔谢维奇博士则回应道，逆转疾病并不意味着非要靠残酷的毅力去强撑，关键在于认清前进的逻辑路径，做出可持续、真正能让人产生热情的生活选择。
### [01:06:59](https://www.youtube.com/watch?v=qqabbfk9wV8&t=4019s) 观察大便：窥探肠道微生态的免费窗口
健康的饮食选择不应让人感到痛苦，而应带来活力与愉悦，使人远离疾病并实现健康长寿，正如 Dr. Will Bulsiewicz 所言，他的目标是到了 80 岁时依然能充满活力地与孙辈翩翩起舞。随后，对话切入了一个既务实又接地气的主题——大便（便便）。演播室现场准备了模拟不同形态的粪便模型，作为胃肠道专科医生，Dr. Will 解释了为何大便的形状和质地能够直观反映人体的整体健康。
大便并非单纯的消化残渣，其干重的 60% 实际上来源于微生物本身。因此，无需耗费昂贵资金进行复杂的实验室检测，每次如厕后回头观察马桶，就是了解个人肠道微生物群最直接、最真实的窗口。
```mermaid
flowchart LR
accTitle: 大便与肠道健康关系
accDescr: 展示大便构成及其与肠道微生物群健康评估的关系
A["日常排便观察"] --> B["60% 重量为微生物"]
B --> C["直观反映肠道菌群状况"]
C --> D["评估肠道转运时间与代谢健康"]
```
---
### [01:08:28](https://www.youtube.com/watch?v=qqabbfk9wV8&t=4108s) 从布里斯托分类法到 14 万人的“全英排便大调查”
临床上评估大便形态的经典工具是 20 世纪 90 年代在英国布里斯托市制定的“布里斯托大便分类法”（Bristol Stool Scale），但该原始研究仅基于当地不足 2,000 人的样本。作为健康科技公司 Zoe 的美国医疗总监，Dr. Will 参与推进了多项更大规模的研究：
- **蓝色大便挑战（Blue Poop Challenge）**：全球超 2 万人参与，通过食用添加食用色素的蓝色松饼精准测算“肠道转运时间”（Gut Transit Time）。
- **全英排便大调查（The Big Poo Review）**：英国迄今规模最大的排便专项调查，涵盖 14.2 万人、共 17 个维度的问卷评估。
这项庞大的调查揭示了许多现代人的肠道现状：
- 普通人平均每天排便 **1.7 次**。
- 在英国，每 **5 个人中就有 1 人**受便秘困扰。
- 每 **6 个人中就有 1 人**频繁出现腹泻症状。
---
### [01:10:05](https://www.youtube.com/watch?v=qqabbfk9wV8&t=4205s) 解读布里斯托大便分型：从“完美香蕉便”到腹泻
Dr. Will 逐一拆解了布里斯托分级标准中的 7 种大便类型，并幽默地描述了最理想的状态：
| 类型 | 形态特征 | 临床意义 | 应对与机制 |
|:--- |:--- |:--- |:--- |
| **第 4 型** | 表面光滑如香肠或鱼雷，质地柔软成型 | **黄金标准**（梦寐以求的排便状态） | Dr. Will 戏称排完 4 型后走出洗手间如同自带慢动作摇滚配乐与飞鸽环绕，身体处于极佳状态。 |
| **第 3 型** | 像香肠但表面带有裂隙 | 偏向便秘的轻微边缘状态 | 无需过分担忧，补充水分、膳食纤维并增加运动即可恢复至第 4 型。 |
| **第 2 型** | 团成香肠状但表面凹凸结块（如同挤在一起的大理石弹珠） | 便秘状态 | 肠道水分被过度吸收，排便阻力增大。 |
| **第 1 型** | 坚硬分散的颗粒，如同兔子粪球或高尔夫球 | 严重便秘 | 极难排出，直肠和肛门括约肌常因粪便过于干硬而无法顺畅放松。 |
| **第 5 型** | 边缘清晰的柔软团块 | 偏向腹泻边缘，但属可接受范围 | 常见于摄入极高膳食纤维的人群，并不一定代表病态。 |
| **第 6 型** | 边缘破碎蓬松的糊状块，或成摊的“牛粪饼”状 | 处于腹泻阶段 | 消化转运过快，大便未能有效定型。 |
| **第 7 型** | 全液体状，完全无固体物质 | 严重腹泻 | 肠道受到强烈刺激或感染，水分几乎未被吸收。 |
发表在顶级胃肠病期刊《Gut》上的多项研究表明，处于第 3、4、5 型之间均属相对健康的范畴，其中第 4 型为最佳基准。
---
### [01:13:36](https://www.youtube.com/watch?v=qqabbfk9wV8&t=4416s) 饮食、短链脂肪酸与肠道转运时间
大便形态与日常饮食结构以及肠道转运时间有着极其紧密的生理关联：
- **如何拉出完美的第 4 型大便**：“全英排便大调查”的数据证实，拥有第 4 型大便的人群在膳食纤维和植物性食物的摄入量上明显更高，其饮食结构包含大量的豆类、全谷物、新鲜水果与蔬菜。
- **极端分型的饮食共性**：令人意外的是，第 1 型（严重便秘）与第 7 型（腹泻）人群的饮食具有相似性——两者的膳食纤维摄入量往往均严重不足。
- **高脂与高动物性饮食的便秘倾向**：摄入高脂肪及大量动物制品的人群，大便更容易偏向便秘谱系；而以植物性食物为主的人群排便更为顺畅通稀。
- **第 5 型的良性机制**：某些纯素食或超高纤维摄入者即便出现第 5 型大便也非常健康。这是因为大量发酵纤维促使肠道微生物产生了丰富的短链脂肪酸（SCFAs），这些脂肪酸充当了大便在结肠中滑行的“天然润滑剂”。
- **转运时间的决定性作用**：肠道转运时间若超过 58 小时（食用蓝色松饼后超过 58 小时才排出颜色），便便在结肠中停留过久导致水分被吸干，极易形成第 1 型和第 2 型硬块；转运时间过短则直接导致未脱水的液体腹泻（第 6、7 型）。转运迟缓与第 7 型腹泻在生理学上绝不可能共存。
### [01:15:56](https://www.youtube.com/watch?v=qqabbfk9wV8&t=4556s) 水分吸收、排便时间与大便颜色的奥秘
结肠（大肠）的核心功能之一是从通过肠道的消化残留物中吸取水分。大便在结肠内停留的时间长短直接决定了其质地：肠道转运速度极快时，结肠来不及吸收多余水分，排泄物的水分含量极高；反之，若转运迟缓，结肠持续抽干水分，大便就会变得极度干结坚硬。在探讨完粪便的形态和尺寸后，演播室桌面摆出了红、蓝、黑、绿、白、黄等各种颜色的大便模型，话题由此转向不同颜色背后的健康警讯。
大便呈现正常的棕褐色，关键在于由肝脏分泌的胆汁（Bile）。胆汁在脂肪消化中扮演至关重要的角色：当我们吃下一顿高脂大餐时，胆囊会强烈收缩挤压，将胆汁排入肠道与食物混合，帮助乳化并吸收脂肪。如果这种机制受阻，大便颜色就会发生剧烈改变：
- **白色便（陶土色便）**：若胆道发生阻塞，胆汁无法排入肠道与食物混合，大便就会彻底失去色素，变成惊人的白色。
- **黄色便（脂肪泻）**：当人体无法正常代谢脂肪（例如患有慢性胰腺炎等胰腺疾病，缺乏足够的消化酶），未消化的脂肪便会随大便排出。此时不仅大便发黄，马桶水面上还会漂浮着一层肉眼可见的“油膜”（Oil slick）。
```mermaid
flowchart TD
accTitle: 大便颜色与消化系统功能机制
accDescr: 展现胆汁与脂肪消化如何决定大便颜色，涵盖正常棕色便、阻塞导致的白色便及胰腺问题引起的黄色脂肪泻。
subgraph LiverGallbladder["肝脏与胆囊系统"]
L["肝脏分泌胆汁"] --> GB["胆囊储存并收缩"]
end
subgraph IntestinalFate["肠道消化与色泽演变"]
GB -->|"正常流入肠道乳化脂肪"| Brown["棕色大便 (正常状态)"]
GB -.->|"胆道阻塞 / 无法进入肠道"| White["白色大便 (胆道梗阻)"]
Pancreas["胰腺疾病 (如慢性胰腺炎)"] -.->|"无法分解脂肪"| Yellow["黄色油腻便 (浮有油膜)"]
end
```
---
### [01:18:01](https://www.youtube.com/watch?v=qqabbfk9wV8&t=4681s) 绿色、蓝色大便与饮食、感染的关联
在谈及绿色大便时，Steven 被问到是否经历过，两人幽默互怼；Will 医生随即坦承自己确实有过。绿色排便的原因既有病理性的也有生理性的：
- **病理性绿色便**：由肠道感染引起的严重腹泻，例如感染了贾第鞭毛虫（Giardia）这类寄生虫，肠道排空过快导致胆汁来不及在结肠中降解转化。
- **饮食引起的绿色便**：日常摄入过量的高叶绿素食物。Will 医生透露自己曾每天狂饮 40 盎司（约 1.2 升）的绿色果蔬昔（Green smoothies），导致排泄物直接变成了鲜绿色。
- **蓝色便**：多与饮食色素相关。最常见的情况是短时间内食用了大量蓝莓；另一种情况则是参与肠道健康科研中著名的“蓝松饼测试”（Blue poop challenge），通过摄入特定蓝色染料的松饼来直观测算食物在个人肠道中的完整转运时间。
---
### [01:18:59](https://www.youtube.com/watch?v=qqabbfk9wV8&t=4739s) 警惕血便：年轻化结直肠癌的致命危险与纤维的防线
大便发红最直观关联的是出血。Will 医生明确提出了他的行医铁律："如果你在大便中看到血液，这绝对不正常，这就是找医生检查的直接理由。"
结直肠癌目前已成为英美等国因癌症死亡的第二大死因，仅在美国每年就有约 15 万人确诊。最令人担忧的是发病群体的年轻化趋势：与父母那一辈相比，现今年轻一代在生命周期中被诊断出直肠癌的几率高出 **4 倍**，被诊断出结肠癌的几率高出 **2 倍**。
```mermaid
flowchart LR
accTitle: 红色血便的成因鉴别与早期干预
accDescr: 红色血便在直肠部位的可能来源、防癌干预机制以及饮食引起的良性混淆。
subgraph RedStoolOrigin["下消化道/直肠出血"]
RS["大便带鲜血"] --> RectumCause["直肠局部病变"]
RectumCause --> Hem["痔疮 / 肛裂"]
RectumCause --> Polyp["肠道息肉 (癌前病变)"]
Polyp -->|"肠镜早期切除"| Prevent["彻底阻断结直肠癌"]
end
subgraph BenignDiet["饮食假象"]
Beet["食用甜菜根 (Beets)"] -->|"24-48小时内"| FalseRed["良性红便 (无需恐慌)"]
end
```
针对红色大便的医学洞察与临床建议：
- **切勿自行诊断为痔疮**：即便大便表面包裹的是鲜红血液，可能来源于靠近末端的直肠、痔疮或肛裂，但也极可能是直肠息肉。Will 医生临床上多次遇到年轻患者因“便中带有一点血”前来就诊，肠镜下却发现了巨大的癌前病变息肉；及时在肠镜下切除息肉，便在萌芽阶段拯救了一条生命。
- **年轻化背后的膳食与微生物机制**：肠道微生物组与结直肠癌之间存在全人类癌症中最直接、最强大的关联，现代饮食结构的急剧恶化是主因。新西兰学者 Andrew Reynolds 的研究证实，膳食纤维与短链脂肪酸（SCFAs）构筑了抗癌防线——日常饮食中**每增加 5 克纤维**，罹患结直肠癌的风险就会出现显著下降。
- **饮食引起的良性红便**：吃甜菜根（Beets）会在 24 至 48 小时内将粪便染成红色，属于正常色素代谢，不必过度恐慌。
---
### [01:22:22](https://www.youtube.com/watch?v=qqabbfk9wV8&t=4942s) 黑色柏油便与上消化道隐性出血
黑色大便（黑便）可能源于温和的非病理因素，也可能是危及生命的上消化道出血信号：
- **药物导致的黑便**：服用含有铋剂（Bismuth）的胃药，例如常用于缓解胃部不适的 Pepto-Bismol。连服数天可能导致大便变黑，但形态通常保持普通质地。
- **上消化道慢性出血（GI bleed）**：当胃部或十二指肠发生溃疡或慢速渗血时，血液从消化道上端流下，经历漫长且缓慢的肠道转运过程，红细胞中的铁质被胃酸和肠道细菌氧化变质，到达直肠时已彻底化为黑色。
临床上鉴别良性黑便与真实上消化道出血的核心特征：
- **质地呈柏油状（Tar-like stool）**：出血引起的黑便质地黏稠、发亮、极似沥青。
- **特征性的刺鼻恶臭**：消化分解后的血液排泄物会散发出极具识别度的恶臭。Will 医生表示，在医院走廊里查房时，医生甚至不需要贴近观察，光是隔着空气闻到那股特殊味道，就能立刻判断即将接到一个上消化道出血的紧急会诊。
---
### [01:23:41](https://www.youtube.com/watch?v=qqabbfk9wV8&t=5021s) 商业赞助：对话卡与 Zoe 科学饮食理念
在本节尾声，Steven 插播了两则赞助内容：
- **The Conversation Cards（深度交流对话卡第二版）**：首发与二次发售均迅速售罄。全新第 2 版重新编写了问题，并在卡牌背面设计了 1 至 3 级的情感暴露深度（Vulnerability levels）。从 Level 1 的破冰闲聊到 Level 3 的深层自我剖析，旨在推动人与人之间真实的脆弱与联结。
- **Zoe 营养科学健康计划**：Steven 作为投资人提醒观众，时逢每年一月，各大减肥产品公司充斥着夸大其词的营销话术与时尚节食（Fad diets）。他呼吁人们停止盲目跟风，转而倾听真正的专家与严谨科学；Zoe 倡导的并非极端的饮食限制，而是基于肠道健康与个性化代谢科学的全面改善。
### [01:25:22](https://www.youtube.com/watch?v=qqabbfk9wV8&t=5122s) 肠道微生物群的遗传：分娩方式、母乳与童年微生态定植
在谈及个性化营养与健康习惯后，主持人史蒂文·巴特利特（Steven Bartlett）提出了一个引人深思的问题：双胞胎研究表明两人的肠道菌群差异极大，那么我们究竟能从父母甚至祖父母那里继承多少微生物？威尔·布尔谢维茨（Dr. Will Bulsiewicz）明确指出，人类确实会继承一部分微生物群，而在新生儿时期，婴儿体内的微生物群构成与母亲最为接近。这种母婴之间的微生态传递在传统经阴道自然分娩以及全母乳喂养的情况下最为显著和深远，大自然正是通过这种亲密接触，将有益于健康的微生物种子播撒给新生儿。
然而，这种早期的微生物定植链条若被打破，往往会带来下游的连锁生理反应。布尔谢维茨医生在此坦率分享了自己的家庭经历：他的三个孩子全部是通过剖宫产出生的。他特别强调，有时医疗干预是不可避免的，剖宫产的孩子同样能健康成长，父母不必为此感到内疚。但在宏观科学层面上，剖宫产、奶瓶喂养（替代母乳）以及婴儿期滥用抗生素，确实会对发育中的肠道微生物群造成干扰。大量研究表明，这种微生态发育的早期受损，会直接导致未来罹患肥胖症、过敏性疾病（如食物过敏和哮喘）以及自身免疫性疾病（如乳糜泻和1型糖尿病）的概率显著上升。甚至有前沿研究通过分析婴儿仅6个月或1岁时纸尿裤中的微生物构成，就能提前预测其在未来4到5年内是否会患上过敏或自身免疫性疾病。
```mermaid
flowchart TD
accTitle: 婴儿早期微生态建立与远期健康影响
accDescr: 展示自然分娩母乳喂养与剖宫产抗生素对肠道菌群建立及长远健康的不同路径
subgraph Transmission["微生态垂直传递"]
M["母体微生物环境"] --> N1["自然阴道分娩 + 母乳喂养"]
M --> N2["剖宫产 / 奶瓶配方奶 / 早期抗生素"]
end
subgraph GutDev["肠道菌群发育"]
N1 --> G1["菌群多样性建立与健康免疫训练"]
N2 --> G2["微生态发育紊乱与关键菌缺失"]
end
subgraph Outcomes["远期健康表型"]
G2 --> R1["代谢异常（肥胖倾向增加）"]
G2 --> R2["过敏反应（哮喘、食物过敏）"]
G2 --> R3["自身免疫疾病（乳糜泻、1型糖尿病）"]
end
```
- **母婴微生物垂直传递的核心途径**：经产道的自然分娩过程和母乳中蕴含的活性益生菌与人乳寡糖（HMOs），是建立婴儿初生菌群的最强大载体。
- **早期菌群失调的下游疾病谱**：包括肥胖、食物过敏、哮喘、1型糖尿病以及乳糜泻。
- **婴儿纸尿裤研究预测价值**：通过检测6个月至1岁幼儿的排泄物微生态特征，能够前瞻性预判其在4至5岁时的过敏与免疫疾病患病风险。
---
### [01:27:14](https://www.youtube.com/watch?v=qqabbfk9wV8&t=5234s) 人际联结与微生态共享：亲密关系如何重塑我们的肠道
肠道微生物群绝非一成不变，它会随着我们的生活经历持续演变。布尔谢维茨医生强调了一项极具震撼力的新研究：人际联结（Human Connection）对微生物组有着直接的生理学塑造作用。研究发现，经常生活在共同空间且保持紧密联系的人，其肠道微生物群的健康度显著高于独居个体；同居伴侣之间共享的微生物，甚至远远超过了具有血缘关系的亲兄弟姐妹。
更令人震惊的发现是亲密关系的“质量”与“张力”。伴侣关系处于一个动态的光谱中，既有甜蜜融洽的高峰，也有疏离冷漠的低谷。研究在严格控制饮食变量后发现，那些情感联结最深厚、关系最亲密的伴侣，彼此间共享的微生物重合度最高；而那些情感疏离、关系冷淡的夫妻，菌群共享度则骤降。这不仅仅是身体接触或性生活频次的差异，而是深层情绪状态投射在微生态上的体现。布尔谢维茨医生感慨道，在当前这个设备绑定、社交媒体泛滥的时代，人们看似无时无刻不在“连接”，实则丧失了面对面注视、倾听与促膝长谈的能力，这种物理孤立与情感隔阂不仅侵蚀心理，更直接削弱了我们的肠道健康。史蒂文赞同地总结道，我们常说身边的社交圈会影响心理，但现在科学证实，周围的人正在通过物理和生物层面深刻改变我们的生理构造与肠道微生物。
- **同居与血缘的对比**：生活在一起的夫妻或伴侣之间共享的微生物丰度，远高于分开生活的亲兄弟姐妹。
- **情感质量与菌群重叠**：研究排除了饮食一致性的干扰，证实关系紧密程度直接正相关于伴侣间微生物组的重合度。
- **现代科技的逆向冲击**：手机与社交软件削弱了面对面的深度社交，导致现代人面临前所未有的微生态孤立。
---
### [01:29:25](https://www.youtube.com/watch?v=qqabbfk9wV8&t=5365s) 压力与童年创伤：肠道是情绪的物理镜像
布尔谢维茨医生指出，情绪与生理是无法割裂的整体，一个人的情绪状态必然会在肠道中显现出来。在急性场景下，压力会迅速转化为肠道反应：例如不习惯公开演讲的人，上台前可能只是轻微心慌、反胃恶心，但严重时这种压力能迅速滚雪球般演变成剧烈的、令人蜷缩弯腰的腹部绞痛（"fold-you-over type cramps"）。许多人正是通过这种方式直观体验到了“肠-脑轴”的惊人威力。
然而，更具破坏性的是长期生活在重压与创伤之中。一项针对2岁前被收养幼儿的开创性研究表明，尽管这些孩子在意识层面完全无法记起2岁前的经历，但功能性磁共振成像（fMRI）扫描显示，他们的大脑激活方式、对压力的神经应激反应以及肠道微生物群结构，都已经留下了不可磨灭的创伤烙印。在临床实践中，布尔谢维茨医生经常遇到许多陷入绝境的患者，他们哭诉自己严格执行了医嘱的所有规范：“Dr. B，我吃得极度健康，睡眠规律，每天坚持锻炼、练瑜伽、做冥想，可为什么肠道问题依然没有好转？”
经过几次随访建立起深厚的信任后，患者往往会卸下防备，向他倾诉深埋在心底的童年创伤或重大精神打击。布尔谢维茨医生每次都会明确地告诉他们：“这正是根源所在。”情绪创伤如同一副沉重的铁链，将身体的自愈机制死死锁住。唯有当心底深处的创伤伤口被正视和疗愈时，肠道才能真正迎来新生。一旦解开这些束缚的心灵锁链，这些患者就像“点火升空的火箭”一样一飞冲天（"they shoot to the moon"），此前积累的健康饮食和生活习惯瞬间全盘激活。布尔谢维茨医生动情地坦言，在自己的整个行医临床生涯中，目睹患者疗愈创伤后彻底摆脱肠道疾病的喜悦，远比教会一个病人多吃膳食纤维更有成就感、更具回报意义。
- **急慢性压力的肠道映射**：
- *急性应激*：公开演讲、考试等诱发胃部翻江倒海、恶心反射乃至痉挛性腹痛。
- *慢性创伤*：童年早期创伤会在潜意识甚至无记忆阶段重塑神经反应模式与肠道微生态。
- **神经影像学证据**：2岁前被收养儿童的 fMRI 脑成像证实，早期创伤直接改变了脑部神经激活机制并同步表现在肠道菌群失调上。
- **创伤疗愈的临床意义**：心理创伤构成了生理康复的无形阻碍；唯有解开心灵创伤的枷锁，饮食与运动等外在干预才能充分发挥疗效。
---
### [01:33:01](https://www.youtube.com/watch?v=qqabbfk9wV8&t=5581s) 酒精对肠道菌群的破坏：宿醉绝非仅仅是脱水
话题转向现代人的日常习惯时，史蒂文提到自己最近彻底戒掉了酒精，布尔谢维茨医生随即为他的决定由衷喝彩。布尔谢维茨医生首先自我剖析并诚实地承认，自己作为一个不完美的人，目前并没有做到百分之百滴酒不沾；但如果抛开个人习惯、单从严谨的科学事实来看，酒精对肠道的损伤是板上钉钉且极其明确的。
他用一个极其形象的生活例子来说明酒精的本质：如果在演播室录制结束后，大家想把面前的桌子彻底消毒清理干净，会用什么？显然会拿出医用外用酒精（rubbing alcohol）喷洒擦拭，因为酒精能够无差别地杀死微生物。同理，当人类将酒精饮料喝进肚子里时，进入消化道的酒精扮演的正是毁灭微生物的角色。与此同时，布尔谢维茨医生驳斥了大众对于“宿醉”的传统认知。公众普遍认为大醉后的恶心、头痛、浑身无力纯粹是“身体脱水”造成的，但他坚决否认了这一观点。根据他深入研究的大量文献，宿醉的本质是酒精对肠道上皮细胞屏障的直接破坏、肠道微生态的大面积凋亡失衡以及随之引发的全身性急性炎性反应，而绝非仅仅喝几杯水补充水分就能解决的简单脱水。
- **酒精的本质杀菌机制**：日常用酒精擦拭桌面是为了灭菌消毒，饮入体内的酒精同样在肠道内对共生微生物实施无差别破坏。
- **关于宿醉认知的科学纠偏**：宿醉的核心生理机制是微生态崩溃与肠黏膜损伤诱发的系统性毒性与炎症，将宿醉等同于单纯“脱水”是一种极大的医学误解。
### [01:33:46](https://www.youtube.com/watch?v=qqabbfk9wV8&t=5626s) 宿醉背后的真相与酒精对肠道屏障的损伤
威尔·布尔希维茨博士（Dr. Will Bulsiewicz）指出，人们在饮酒后体验到的宿醉，其深层本质是肠道微生物群遭受了严重破坏。这也是为什么人们往往需要整整二十四小时甚至更久，身体才能逐渐恢复元气，重新“感觉自己像个正常人”。酒精对身体的摧残绝非仅限于肝硬化等肝脏疾病，诸多全身性慢性疾病都与酒精摄入紧密相关。现行公共卫生指南中所谓“男性每天适量饮酒最多三杯、女性两杯”的标准在布尔希维茨博士看来极其荒谬，因为这个饮酒量其实非常庞大。
彻底改变博士认知的，是一项监测血液中细菌内毒素——即脂多糖（Lipopolysaccharide, LPS）水平的研究。脂多糖原本只应存在于肠道内，绝不应该穿透肠壁进入血液循环；一旦在血液中检测到它，就意味着肠道屏障结构已经受损（即肠漏），进而引发强烈的全身性炎症反应。这项研究揭示了令人震惊的数据：血液中的酒精浓度曲线与脂多糖浓度曲线几乎呈绝对平行的走势——血液酒精含量上升，内毒素水平随即飙升；酒精代谢下降，内毒素水平才随之回落。这证明即使是饮用极少量的酒精，也足以在短时间内撕开肠道防护网，使肠道微生物遭受重创并引发全身性慢性炎症。
```mermaid
flowchart TD
accTitle: 酒精破坏肠道屏障导致全身炎症机制
accDescr: 展示酒精摄入如何直接破坏肠道内壁，导致脂多糖内毒素漏入血液循环并引发系统性炎症。
subgraph GutLumen["肠道微环境"]
Alcohol["摄入酒精"]
Microbiome["微生物菌群受损"]
LPS["释放细菌内毒素 / 脂多糖 (LPS)"]
end
subgraph BarrierDamage["肠壁屏障"]
LeakyGut["肠黏膜屏障破损（肠漏）"]
end
subgraph SystemicCirculation["血液循环与全身反应"]
Bloodstream["LPS进入血液循环<br/>（浓度与血醇浓度平行同步）"]
Inflammation["触发全身系统性炎症<br/>与严重宿醉反应"]
end
Alcohol --> Microbiome
Alcohol --> LeakyGut
Microbiome --> LPS
LPS --> LeakyGut
LeakyGut --> Bloodstream
Bloodstream --> Inflammation
```
### [01:35:31](https://www.youtube.com/watch?v=qqabbfk9wV8&t=5731s) 脑肠轴：肠道如何掌控情绪与大脑运作
谈及“脑肠轴”（Brain-Gut Connection），布尔希维茨博士用非常形象的比喻解释道：“肠道最好的朋友就是大脑”，二者时时刻刻都在保持高频通讯，密不可分。肠道向大脑传递信号的核心通道之一是神经递质系统。许多人误以为主管情绪的血清素（Serotonin）主要来源于大脑，但事实上，人体中 95% 的血清素都是由肠道细胞制造的，大脑内部合成的血清素仅占总量的 5%。这种被称为“快乐荷尔蒙”的物质深刻影响着人体的精力、专注力以及整体情绪状态；在治疗重度抑郁症时，医学界正是通过提高血清素水平来改善症状，而肠道在这其中扮演了主力工厂的角色。
此外，作为“奖励荷尔蒙”的多巴胺（Dopamine），全身体内约有 50% 同样产自肠道。整个肠道系统能够分泌多达 30 余种神经递质。连接这两大器官的核心通信桥梁是迷走神经（Vagus Nerve），布尔希维茨博士将其比喻为一条跨洋专线电话：“就像你在伦敦，而我在美国，我拿起电话直接说：‘嘿，史蒂文，我有事找你。’肠道正是通过这条超级专线实时向大脑汇报情况。”除了神经信号，肠道微生物在发酵纤维后产生的后生元代谢物——短链脂肪酸（SCFAs），能够直接穿透血脑屏障，对人类的情绪与注意力产生实质调节作用。针对儿童进行的一项专注力障碍研究便证实，增加体内的短链脂肪酸水平能够显著提升孩子们的专注力。
- **血清素（Serotonin）**：95% 在肠道产生，仅 5% 产自大脑，直接调节精力、专注力及正面情绪。
- **多巴胺（Dopamine）**：50% 在肠道合成，主导奖励机制与动力。
- **神经递质网络**：肠道可合成与释放超过 30 种不同类型的神经递质。
- **迷走神经专线**：构成大脑与肠道之间的双向即时物理连接通道。
- **代谢产物直接入脑**：短链脂肪酸等微生物代谢物能越过血脑屏障，直接影响神经功能。
### [01:37:28](https://www.youtube.com/watch?v=qqabbfk9wV8&t=5848s) 短链脂肪酸：最强天然抗炎分子与“肠道如肌肉”训练法
短链脂肪酸是博士在著作中着重强调的“大自然中治愈力最强的营养素”，也被他评为“迄今为止所见过的最具抗炎特性的分子”。人体摄入膳食纤维或抗性淀粉后，体内的肠道微生物便会像魔法师一样将它们分解并发酵生成短链脂肪酸。但这仅仅是传奇的开端：人体的免疫细胞和体细胞表面密布着专门接收短链脂肪酸的受体，短链脂肪酸借此充当信号传导分子，精准向人体下达指令、甚至控制基因的开启与关闭。
以自身免疫性疾病为例，足够的短链脂肪酸能够赋能并激活具有刹车功能的调节性 T 细胞（T regulatory cells），从而及时平息免疫系统的过度激惹，避免免疫系统攻击自身器官。博士强调，人类的基因组在过去两三百年间并没有根本改变，然而在过去半个世纪中，各类自身免疫性疾病的患病率却暴增了 500%，许多病种在一个世纪前甚至连名字都没有。这种急剧飙升显然不能归咎于遗传学，其根本诱因在于现代生活方式与饮食结构的崩溃，导致肠道微生物群丧失了足够的膳食纤维供给。
面对纤维摄入，博士重申了“低量起步、循序渐进”的原则，并提出了**“肠道如肌肉”**的经典理论：
> “肠道就像一块肌肉。肌肉拥有做功的能力，但它也存在承载极限。一块肌肉经过越多的训练，它的做功上限就越高。就像你在卧推时，可能从 50 公斤起步，逐渐增加到 55 公斤、60 公斤，力量正是这样一步步增强的。你的肠道也是完全相同的运作逻辑。”
如果让肠道持续接触丰富多样的食物，肠道微生态及其消化酶系就在接受适应性训练，消化能力便会水涨船高，最终摆脱受限饮食的束缚，获得极大的食物耐受宽容度。
### [01:41:02](https://www.youtube.com/watch?v=qqabbfk9wV8&t=6062s) 纤维的多样性与两大功能阵营
针对史蒂文关于“所有膳食纤维是否完全一样”的提问，布尔希维茨博士明确给出了否定回答。“纤维”一词和“蛋白质”一样，只是一个宽泛的统称，没有人会把鱼肉中的动物蛋白与豆类中的植物蛋白混为一谈。大自然中的每一种植物都蕴藏着其特异性的纤维类型，其复杂与繁复程度甚至尚未被科学完全穷尽。然而在基础生理分类上，膳食纤维主要划分为两大阵营：
1. **可溶性纤维（Soluble Fiber）**：
这类纤维极易溶解于水，融入饮品中后完全透明不可见。可溶性纤维的核心使命是担当优质益生元（Prebiotics），成为滋养肠道有益菌群的主要口粮，驱动短链脂肪酸的大量生成。
2. **不可溶性纤维（Insoluble Fiber）**：
这类纤维质地粗糙，即使加水煮沸也无法溶解，保持颗粒状或纤维原貌。虽然它通常不直接充当细菌的食物，但它能够刺激肠道蠕动、改善排便顺畅度与肠道排空时间，同时在降低胆固醇和调控血脂指标方面发挥着不可替代的代谢支持作用。
布尔希维茨博士总结道，普通大众无需在日常生活中对可溶性与不可溶性纤维进行繁琐的区分和计算；最重要的铁律在于认识到“植物含有纤维，且每种植物都含有其独一无二的纤维结构”。摄入的植物种类越丰富，喂养的肠道菌群家族就越多元完整。随后，史蒂文引出了博士在书中极力推崇的“F-GOALS”高纤维植物饮食框架，开启了后续针对最佳饮食策略的深入探讨。
### [01:42:55](https://www.youtube.com/watch?v=qqabbfk9wV8&t=6175s) 肠道多样性饮食的核心法则：“F GOALS”框架
谈及饮食模式时，威尔·布尔谢维奇博士（Dr Will Bulsiewicz）强调，他不希望人们将“节食”（Diet）视为一种无法持续的短期限制手段。肠道健康领域目前最大的误区在于：人们总是在迫不及待地从饮食中剔除、限制各类食物，却极少思考如何主动做“加法”。健康饮食的核心应是“丰富度”（Abundance）。为此，他在著作《纤维燃料》（Fiber Fueled）中提出了用于规划日常饮食的多样性框架——**F GOALS**，每个字母代表一类能够滋养肠道菌群的关键食物类别：
```mermaid
flowchart TD
accTitle: F GOALS 食物分类体系
accDescr: 展示 Dr Will 提出的 F GOALS 八大类滋养肠道微生物的核心食物
subgraph FG["F & G: 基础果蔬与谷物"]
F["F - 水果 & 发酵食物<br/>(Fruit & Fermented)"]
G["G - 绿叶菜 & 未精制全谷物<br/>(Greens & Whole Grains)"]
end
subgraph OA["O & A: 脂肪酸与芳香物"]
O["O - Omega-3 超级种子与核桃<br/>(Chia, Flax, Hemp, Walnuts)"]
A["A - 葱属芳香类蔬菜<br/>(Onions, Garlic, Shallots)"]
end
subgraph LS["L & S: 核心超级食物"]
L["L - 豆类超级食物<br/>(Beans, Peas, Lentils)"]
S["S - 蘑菇、海藻与活力芽菜<br/>(Shrooms, Seaweed, Sprouts)"]
end
FG --> OA --> LS
```
- **F（Fruit & Fermented）**：包含水果与发酵食品。博士指出，水果在现代饮食文化中遭受了不公正的“污名化”；事实上，多吃水果的人患糖尿病的概率更低，且更有利于减重。发酵食品则能直接为肠道微生物群补充菌种多样性。
- **G（Greens & Grains）**：包含绿叶蔬菜与未精制全谷物。绿叶菜热量极低且营养密度极高；未精制全谷物富含膳食纤维和抗性淀粉，是肠道有益菌不可或缺的优质食粮。
- **O（Omega-3 Super Seeds）**：富含 Omega-3 的超级种子与坚果，如奇亚籽（chia seeds）、亚麻籽（flax seeds）、大麻籽（hemp seeds）以及核桃（walnuts），能为人体补充必需的优质健康脂肪。
- **A（Aromatics）**：葱属芳香蔬菜，包括洋葱、大蒜和红葱头（shallots）。它们不仅赋予菜肴风味，更富含保护心血管、抵御癌症的生物活性成分。
- **L（Legumes）**：豆类（豆子、豌豆、小扁豆）。布尔谢维奇博士将其视作心目中“排名第一的超级食物”，不仅对肠道微生态极其有益，更是长寿饮食的核心；大量临床证据证实豆类能全面降低心血管疾病、癌症、中风和糖尿病的发病风险。
- **S（Shrooms, Seaweed & Sprouts）**：涵盖三类独特的超级食物。蘑菇（Shrooms）虽属于真菌而非严格意义上的植物，却因富含特殊纤维被视作“荣誉植物”；海藻（Seaweed）如日本饮食中的藻类，蕴含独特的纤维与微量元素；芽菜（Sprouts，如西兰花芽菜，最初在书中以萝卜硫素 Sulforaphane 命名）则是名副其实的超级营养库。博士解释道，种子只需清水便能“解锁大自然的生机密码”，发芽过程会爆发性释放高浓度的蛋白质、膳食纤维和植物化学物，一小撮西兰花幼芽所含的抗癌化合物浓度是成年成熟西兰花的50到100倍，吃一撮芽菜的健康收益堪比吃下一整颗花椰菜。
---
### [01:47:02](https://www.youtube.com/watch?v=qqabbfk9wV8&t=6422s) 代际微生态流失：不可逆的菌群代际递减与西方饮食陷阱
当父母遵循富含纤维的多样化饮食时，其收益不仅限于自身，更会通过微生物群的垂直传递深刻影响下一代。史蒂芬·巴特利特（Steven Bartlett）由此引出了一项关于西方饮食与微生物多样性随代际衰退的经典小鼠实验。布尔谢维奇博士指出，这项研究由斯坦福大学著名微生物学家贾斯汀·索嫩伯格（Justin Sonnenburg）主持（索嫩伯格亦为其著作《纤维燃料》撰写了推荐语）。
人类世代繁衍通常需要30年甚至更长时间，因此研究人类几代人间的微生态演变极为困难，但小鼠模型能在短周期内揭示这一规律。索嫩伯格团队让具有丰富菌群多样性的小鼠长期摄入低纤维的“典型西方饮食”：
- **第一代小鼠**：因膳食纤维匮乏，肠道微生物多样性出现显著滑坡；当其繁殖后代时，传给幼崽的菌群丰度已大打折扣。
- **后续世代的复合衰减**：子代小鼠在持续的低纤维饲养下，菌群多样性进一步枯竭，并继续将这种严重退化的微生态传递给下一代。
- **饮食干预的局限性**：如果在代际传递中途重新向小鼠饲料中添加膳食纤维，虽然能够部分唤醒并恢复休眠的肠道菌群，却**再也无法彻底恢复到最原始的菌群基线**。部分菌种在漫长的低纤维代际演变中已经彻底灭绝。
博士举例形象地说明了这种危害：如果外祖母童年时肠道内拥有1200种微生物，因饮食习惯变差，到母亲出生时只剩下900种；母亲若在成长中再次丢失300种菌株，那么你出生时能继承的基准菌群就只剩下600种——整整损失了外祖母拥有的一半丰度。肠道内的每一种微生物都在协同演化中承担着特定功能，当关键物种永久缺位时，其他幸存菌群往往无法完全接替这些职责。
更为重要的是，现代医学常将某些家族高发的慢性疾病归咎于“遗传基因”。然而布尔谢维奇博士与佐伊健康项目（Zoe）的联合创始人蒂姆·斯佩克特教授（Dr Tim Spector）的基因组研究发现，许多家族聚集性疾病并不能单靠基因解释。代际传递的核心真相，不仅是残缺微生物群的物理移交，更是**不良家庭生活方式与饮食结构的代代相传**；父母若无法为自身创造健康的微生态环境，便会将致病的生活习惯与受损的菌群底盘同时复制给孩子。
---
### [01:50:37](https://www.youtube.com/watch?v=qqabbfk9wV8&t=6637s) 肠道微生物与性健康：“雌激素组”对荷尔蒙平衡的调控机制
对话最后转向了性健康与肠道微生物群之间鲜为人知的隐秘联系。史蒂芬提及前文讨论过的勃起功能障碍、费洛蒙（Pheromones）以及性冲动，询问肠道菌群究竟如何直接或间接影响人类的性欲、勃起状态与性生活质量。
布尔谢维奇博士首先从病理生理学常识切入：当人体处于生病或慢性炎症状态时，肠道微生态必然受到重创，此时身体会出于自我保护机制关闭繁殖与性冲动，“性欲消失本身就是疾病状态的一部分”。除此之外，性欲的高低在内分泌层面受到体内各类荷尔蒙水平的严格调控，而肠道微生物群正是人体多项激素代谢的关键操纵者。
针对女性群体，博士重点介绍了**雌激素组（Estrobolome）**这一科学概念。雌激素组特指肠道内能够代谢并调控人体雌激素循环的特定微生物集群：
- **雌激素的肠道循环守门人**：体内的雌激素在代谢过程中呈现出一种循环模式——它既可以随着粪便被直接排出体外，也可以在肠道内被重新解离、再次吸收入血。
- **重吸收与排出的精准控制**：肠道中的“雌激素组”微生物正是决定雌激素去留的“守门人”。如果肠道菌群失调，特定酶类活性改变，可能导致过多雌激素被重新吸收入血液循环，破坏体内荷尔蒙平衡。
- **雌激素驱动型疾病的根源**：正是由于肠道菌群对雌激素重循环的调控失衡，许多典型的雌激素依赖性疾病——包括乳腺癌（breast cancer）、卵巢癌（ovarian cancer）、子宫内膜癌（endometrial cancer）以及子宫内膜异位症（endometriosis）——其发生与恶化都与患者肠道微生态的紊乱呈现出高度的相关性。
### [01:52:08](https://www.youtube.com/watch?v=qqabbfk9wV8&t=6728s) 肠道菌群与性激素：从睾酮到多囊卵巢综合征
Dr Will 深入探讨了肠道微生态与性激素之间密不可分的双向联系。目前的临床观察显示，在多种激素失衡的情况下，几乎都能观察到肠道菌群受损的现象。虽然这仍属于强烈暗示而非完全证实的因果链条，但越来越多的证据表明，肠道菌群失调可能正是驱动雌激素水平异常的关键推手。这种机制同样适用于雄激素（睾酮）。男性体内自然存在雌激素，女性体内也拥有雄性激素，区别仅在于两性间的优势主导激素不同。
科学家已经发现某些特定菌株能直接操纵激素代谢，例如脱氧胆酸产生菌（*Clostridium scindens*，裂解梭菌）便已知能影响男性的睾酮水平。在女性群体中，常见的多囊卵巢综合征（PCOS）的核心机制正是雌激素与雄激素之间的平衡被严重打破，而肠道菌群被普遍怀疑是这场代谢与激素风暴的核心枢纽。由于性欲、性功能以及勃起等生理反应皆受激素驱动，肠道菌群必然深涉其中。Dr Will 指出，尽管女性性欲受限于缺乏明确的诊断标签而较少被针对性研究，但他深信女性的性唤起与欲望同样与肠道微生物紧密相连。
- **裂解梭菌（*Clostridium scindens*）**：被证实参与体内激素转化，直接影响男性的睾酮水平。
- **多囊卵巢综合征（PCOS）**：雌激素与雄激素失衡导致该疾病表现，肠道菌群在其中扮演中枢调节角色。
- **性功能与菌群的内在联系**：从男性勃起功能障碍（ED）到两性的性冲动，均受肠道微生物调控的激素网络所支配。
---
### [01:53:38](https://www.youtube.com/watch?v=qqabbfk9wV8&t=6818s) 微生物红娘：吸引力、信息素与配偶选择
Dr Will 提出了一个极富趣味的核心假说：微生物在人类两性配偶选择中可能扮演着“红娘”（Matchmaker）的角色。他结合自己的生活经历谈到，虽然自己已经结婚十年、告别单身生活已久，但很多人都有过相亲或约会的共鸣——有时候对方的人格魅力毫无问题，但仅仅是闻到对方身上的某种气味，或者在接吻的那一瞬间，直觉就会立刻亮起红灯：“这行不通，完全没有火花。”
Dr Will 坚信，这种生理层面的“化学反应”或“不兼容感”很大程度上源自肠道微生物。长久伴侣之间会通过亲密接触互相分享和重塑彼此的菌群，因此身体本能地在寻找微生物层面匹配的伴侣。动物研究已经清楚表明，信息素（费洛蒙）的浓度、个体的体味乃至“吸引力荷尔蒙”的释放，都直接与肠道菌群的状态挂钩。从接吻时菌群的交换，到散发出的信息素，再到内在的性欲望，整个吸引力网络都被微生物的丝线串联在一起。
```mermaid
flowchart TD
accTitle: Gut Microbiome and Human Attraction
accDescr: 展现肠道微生物如何通过激素、信息素、外在表象和亲密接触驱动两性吸引力与配偶选择。
subgraph Internal ["体内微生物驱动"]
M["肠道菌群状态"] --> H["性激素平衡<br/>(雌激素/睾酮)"]
M --> P["信息素与体味<br/>(费洛蒙释放)"]
M --> V["健康外显特征<br/>(透亮皮肤/形体活力)"]
end
subgraph Attraction ["配偶选择与吸引"]
H --> L["性冲动与勃起功能"]
P --> A["嗅觉与气味兼容性"]
V --> S["视觉层面的生理健康美"]
end
subgraph Intimacy ["亲密互动"]
L & A & S --> K["接吻与亲密接触"]
K --> SH["伴侣间微生态共享"]
SH --> M
end
```
针对 Steven 幽默的提问（“如果我想更有吸引力，是不是多吃点豆芽就行了？”），Dr Will 阐述了吸引力与健康的本质：虽然个体审美各异——这种审美多样性也是维持人类基因池丰富度的必要演化机制——但人类对吸引力的底层标准存在普适共识，即“健康指标”。人们习惯把吸引力归因为可见的肉眼特征（容貌、体态）或可听的行为特征（幽默感、机智、谈吐），但这些外在现象根本无法与看不见的内在生理状态切割。皮肤的光泽透亮、年轻态的外貌以及充满活力的身形，本质上都是肠道深处微生态健康的投射。
---
### [01:56:53](https://www.youtube.com/watch?v=qqabbfk9wV8&t=7013s) 38 Tera 补剂与肠道修复终极法则
对话转入针对日常微生态调理的解决方案。Steven 提及自己录制期间一直在饮用 Dr Will 自主研发的益生元冲剂——**38 Tera**。Dr Will 解释道，“38 Tera”代表的是 38 万亿（38 Trillion），象征着栖息在人体内保护我们健康的 38 万亿个微生物。该产品名为“每日微生态营养粉”（Daily Microbiome Nutrition），采用经过临床验证的特定功效成分与剂量，旨在改善肠道微生态、平息消化道不适，并帮助人们将便便从 Bristol 评分系统中的 1、2 型（便秘干硬）或 6、7 型（腹泻稀便）调理回完美的 4 型状态。Steven 对此赞不绝口，表示其口感刷新了对营养补剂的认知，不知不觉就喝光了一整瓶。
在总结全期访谈的核心理念时，Dr Will 为听众梳理出一套切实可行的生活行动指南：
- **拥抱植物多样性**：大量且广泛地摄入水果、蔬菜、全谷物、坚果、种子以及豆类，每一类植物都在为特定菌群提供养分，甚至“咖啡也算一种植物摄入”。
- **纳入发酵食品**：积极向日常饮食中增加发酵食品以补充活菌与活性代谢产物。
- **践行低成本生活方式**：走向户外多做运动、确保充足且高质量的夜间睡眠。
- **注重真实的人际连结**：去拥抱在乎的人，维系深层次的社交情感支持。Dr Will 强调，这些至关重要的养生法则大多是完全免费的。
该产品已在 38tera.com 上线，并计划于 1 月中旬率先在美国和澳大利亚正式发售，英国及其他地区的消费者虽然面临运费成本，但同样可以订购。
---
### [01:59:16](https://www.youtube.com/watch?v=qqabbfk9wV8&t=7156s) 终极问题：何为真正的幸福？
节目进入《CEO日记》的标志性传统收尾环节：由上一位未曾谋面的嘉宾向 Dr Will 留下一个私人问题——**“在你的人生中，你何时最感到幸福？你可以用任何你喜欢的方式来定义‘幸福’。”**
面对这个问题，Dr Will 的回答深情而朴实。他指出，现代社会的一个通病在于过度痴迷于诸如财富、金钱等可量化的客观指标，却遗失了那些无法被精准度量却构成生命本质的东西。
> “我完全不知道你在家里过得有多幸福，我无法衡量；我或许大致能猜到你的财务状况。然而，幸福才是生命的本质所在。对我而言，幸福完全来自于我的家庭。”
Dr Will 坦言，镜头前无论表现得多么专业，离开录影棚后每个人都是过着平凡日子的真实个体。唯有在南卡罗来纳州查尔斯顿（Charleston）与他朝夕相处的挚友，才能看到最本真的他。他所追寻的终极快乐，就是倾尽全力去为家人奋斗、守护他们，并全身心沉浸在与家人共度的时光之中。Steven 对此致以由衷的赞叹，高度评价 Dr Will 不仅拥有无与伦比的深厚学识，更具备罕见的沟通天赋，正引领全社会开启一场认知自身微生态的伟大变革。
### [02:00:59](https://www.youtube.com/watch?v=qqabbfk9wV8&t=7259s) 传播健康认知与致谢：Dr. Will 的全网联络方式与访谈简报发布
Steven Bartlett 在访谈尾声对 Dr. Will Bulsiewicz 表达了由衷的敬意与感谢。Steven 指出，深入了解自身健康与肠道机制能够解锁人们一生所追求的终极目标——也就是“幸福”（Happiness）。Dr. Will 的科普工作实质上是在提升公众的幸福感，这是一项极其崇高且有价值的使命。代表所有无法亲自当面致谢的广大听众，Steven 对 Dr. Will 毫无保留的专业分享致以真挚的谢意。
Dr. Will 随后向听众介绍了继续深入交流与获取科学知识的渠道。他开玩笑地提到，自己在 Instagram 和 Facebook 上的账号均为 `@theguthealthmd`，而 TikTok 账号因为原用户名被一名 14 岁少年抢注，只能使用 `@theguthealthmd_`。此外，听众还可以访问他的官方网站 `theplantfedgut.com` 订阅免费的电子邮件通讯（Newsletter）。Dr. Will 强调，邮件通讯是他深度拆解最新科学论文和研究成果最有效的方式；同时，大家也可以在网站上了解他研发的微生态健康产品 38 Tera。
为了帮助听众消化本期信息量巨大的对话，Steven 宣布了一项此前从未做过的全新举措：节目组将把团队为本期访谈精心准备的背景研究浓缩为一份约 10 页的深度访谈简报（Interview Brief），直接免费放入节目描述栏中。这样一来，无论听众是在洗碗、通勤乘地铁，还是进行多任务处理，都能通过简报轻松复习核心结论与实操建议。此外，描述栏还将附带对话中反复提及的“布里斯托大便分类法”（The Bristol Stool Chart）以及 Dr. Will 的全网链接。
- **社交平台与官网**：Instagram/Facebook (`@theguthealthmd`)、TikTok (`@theguthealthmd_`)、官网 `theplantfedgut.com`。
- **10页深度简报**：总结关键要点（Key Takeaways）与实操洞察（Actionable Insights），旨在辅助多场景收听体验。
- **参考资料提供**：附带布里斯托大便分类法图表与 38 Tera 益生元补剂详情。
---
### [02:02:53](https://www.youtube.com/watch?v=qqabbfk9wV8&t=7373s) 赞助推荐与延伸收听：Huel 专属套装及下期节目引导
在节目的片尾广告中，Steven Bartlett 介绍了长期赞助播客并由他本人投资的代餐与营养品牌 Huel。为了方便初次尝试或想要选购其心仪产品的听众，Steven 推出了一款特别定制的“Steven 套装”（Steven Bundle）。该组合包含了 Steven 日常高频使用的多款产品，尤其是高蛋白配方的 Black Edition 海盐焦糖风味粉剂（每桶 17 份份量），以及专为忙碌日程准备、营养完整的开盖即饮版（Ready-to-drink）代餐瓶。
该套装还附带口感出色的 Huel 能量棒、经典摇摇杯，以及一件据 Steven 身边多位朋友反馈“版型格外显身材、质感极佳”的 Huel 定制纯色 T 恤。所有选购链接均已放置在各平台的节目介绍栏中。最后，Steven 提示听众，数据算法显示喜欢本期肠道健康话题的观众通常也会对另一期相关访谈（如 Dr. Tim Spector 教授关于微生态与个性化营养的深度对话）产生浓厚兴趣，建议听众点击描述栏中的推荐链接继续收听。
## Notable quotes
> [02:13](https://www.youtube.com/watch?v=qqabbfk9wV8&t=133s) 我们就是专门负责研究‘肠子和屁股（guts and butts）’的专家。 — Dr. Will Bulsiewicz
> [03:59](https://www.youtube.com/watch?v=qqabbfk9wV8&t=239s) 欢迎来到这个世界，来看看你终生的共生伙伴吧，它们将在此后一生中保护你、成就你的健康。 — Dr. Will Bulsiewicz
> [18:49](https://www.youtube.com/watch?v=qqabbfk9wV8&t=1129s) 肠道具有极强的宽容度（the gut is forgiving）。 — Dr. Will Bulsiewicz
> [40:06](https://www.youtube.com/watch?v=qqabbfk9wV8&t=2406s) 起步要低，增量要慢（start low and go slow）。 — Dr. Will Bulsiewicz
> [01:03:25](https://www.youtube.com/watch?v=qqabbfk9wV8&t=3805s) 生活中的每一种捷径往往都标好了代价。 — Steven Bartlett
> [01:18:59](https://www.youtube.com/watch?v=qqabbfk9wV8&t=4739s) 如果你在大便中看到血液，这绝对不正常，这就是找医生检查的直接理由。 — Dr. Will Bulsiewicz
> [01:35:31](https://www.youtube.com/watch?v=qqabbfk9wV8&t=5731s) 肠道最好的朋友就是大脑。 — Dr. Will Bulsiewicz
> [01:37:28](https://www.youtube.com/watch?v=qqabbfk9wV8&t=5848s) 肠道就像一块肌肉。肌肉拥有做功的能力，但它也存在承载极限。一块肌肉经过越多的训练，它的做功上限就越高……你的肠道也是完全相同的运作逻辑。 — Dr. Will Bulsiewicz
> [01:50:37](https://www.youtube.com/watch?v=qqabbfk9wV8&t=6637s) 性欲消失本身就是疾病状态的一部分。 — Dr. Will Bulsiewicz
> [01:59:16](https://www.youtube.com/watch?v=qqabbfk9wV8&t=7156s) 我完全不知道你在家里过得有多幸福，我无法衡量；我或许大致能猜到你的财务状况。然而，幸福才是生命的本质所在。对我而言，幸福完全来自于我的家庭。 — Dr. Will Bulsiewicz
## Mentioned
Dr. Will Bulsiewicz, Steven Bartlett, Dr. Tim Spector, Lawrence David, Justin Sonnenburg, Andrew Reynolds, Elon Musk, Zoe, Huel, 38 Tera, The Diary Of A CEO, Fiber Fueled, The Bristol Stool Scale, American Gut Project, PREDICT 1 Study, Ozempic, Wegovy, Modafinil, Pepto-Bismol, The Conversation Cards
## Video description
If you enjoy hearing all about gut health with Dr Will Bulsiewicz, I recommend you check out my conversation with Dr Tim Spector, which you can find here: https://www.youtube.com/watch?v=66hWntvp0_4&t=2165s
00:00 Intro
02:16 Why Is The Gut Microbiome So Important?
05:32 What Are Gut Microbes?
10:14 Everyone's Microbes Are Different.
13:35 Link Between The Immune System And The Gut.
17:41 Foods To Improve Gut Health
25:46 Fermented And Prebiotic Foods.
33:13 The Relationship Between Our Gut & Metabolism
35:39 What Your Poo Says About Your Health.
40:24 How Fiber Affects Your Gut.
43:58 How A Poo Transplant Could Improve Health Conditions.
54:42 Calorie Counting.
59:25 Medicine For Losing Weight: Pros & Cons.
01:07:18 What Your Poo Should Look Like.
01:13:29 How To Have A Healthy Gut.
01:16:32 Different Poo Colours And Health Conditions.
01:23:44 Ads
01:25:22 Is The Gut Microbiome Inherited?
01:29:25 Stress Will Affect Your Gut.
01:33:01 How Alcohol Affects Your Gut.
01:35:34 The Brain Gut Connection
01:37:32 How To Heal Your Gut.
01:42:45 The Best Diets.
01:50:31 The Link Between Good Sex And Your Gut.
01:56:55 The Best Supplements For Your Gut.
01:59:17 Last Guest Question.
Additional Interview Information:
Interview Brief: https://drwillbrief.tiiny.site
The Bristol Stool Chart: https://bit.ly/486k4Yo
Dr Will’s supplement: https://38tera.com
You can purchase Dr Will’s book, ‘Fibre Fuelled: The Plant-Based Gut Health Plan to Lose Weight, Restore Health and Optimise Your Microbiome’, here: https://amzn.to/47YuitQ
Follow Dr Will:
Instagram: https://bit.ly/3tyHQgu
Website: https://bit.ly/3tsZum4
Get tickets to The Business & Life Speaking Tour: https://stevenbartlett.com/tour/
FOLLOW ►
Instagram: https://www.instagram.com/steven/
Twitter: https://x.com/StevenBartlett?s=20
Linkedin: https://www.linkedin.com/in/steven-bartlett-56986834/
Sponsors:
The Conversation Cards: https://thediary.com/products/the-cards
Zoe: http://joinzoe.com with an exclusive code CEO10 for 10% off
Huel: https://my.huel.com/daily-greens-uk
[Source](https://www.youtube.com/watch?v=qqabbfk9wV8)
Source quotes
[2:13] Dr. Will Bulsiewicz: 我们就是专门负责研究‘肠子和屁股（guts and butts）’的专家。
[3:59] Dr. Will Bulsiewicz: 欢迎来到这个世界，来看看你终生的共生伙伴吧，它们将在此后一生中保护你、成就你的健康。
[18:49] Dr. Will Bulsiewicz: 肠道具有极强的宽容度（the gut is forgiving）。
[40:06] Dr. Will Bulsiewicz: 起步要低，增量要慢（start low and go slow）。
[63:25] Steven Bartlett: 生活中的每一种捷径往往都标好了代价。
[78:59] Dr. Will Bulsiewicz: 如果你在大便中看到血液，这绝对不正常，这就是找医生检查的直接理由。
[95:31] Dr. Will Bulsiewicz: 肠道最好的朋友就是大脑。
[97:28] Dr. Will Bulsiewicz: 肠道就像一块肌肉。肌肉拥有做功的能力，但它也存在承载极限。一块肌肉经过越多的训练，它的做功上限就越高……你的肠道也是完全相同的运作逻辑。
[110:37] Dr. Will Bulsiewicz: 性欲消失本身就是疾病状态的一部分。
[119:16] Dr. Will Bulsiewicz: 我完全不知道你在家里过得有多幸福，我无法衡量；我或许大致能猜到你的财务状况。然而，幸福才是生命的本质所在。对我而言，幸福完全来自于我的家庭。
Source quotes
[25:04] Dr. Will Bulsiewicz: Fermentation is where we actually grab that process, and we control it. Almost like a magician, we're shaping it.
[109:08] Dr. Will Bulsiewicz: When they're absent, they're not able to do their job. And the other microbes may not be able to step up to actually do what's the job of what's missing.
[119:16] Steven Bartlett: When have you been happiest in your life?
Original transcript
[0:00] What I have here is a variety of
[0:02] different shapes and sizes of poop.
[0:05] Yeah. What does this tell us about our
[0:07] health? Well, if your poop looks like
[0:09] this, to me that's grounds to talk to a
[0:11] doctor. Dr. Will Bulsiewicz,
[0:13] world-renowned gut health doctor.
[0:15] Who has a wealth of information on
[0:17] how we can improve our gut health
[0:19] through food and lifestyle changes. We
[0:21] are currently living through an epidemic
[0:22] of gut health issues, and if we want to
[0:24] be healthy humans, we absolutely need a
[0:27] healthy gut microbiome in order to
[0:28] accomplish that. So, let's break this
[0:30] down. First of all, microbes are
[0:31] invisible. On your thumb, there are as
[0:33] many microbes as there are people in the
[0:35] UK.
[0:36] Really? And gut microbes play a critical
[0:37] and essential role in controlling
[0:39] whether or not you suffer from
[0:40] depression, because 95% of the happy
[0:43] hormone is produced by the gut. It
[0:45] controls your cognition, your memory,
[0:47] your energy levels. Your gut is the
[0:49] place where you are making decisions,
[0:50] and study after study after study shows
[0:52] us that when people eat more
[0:54] not only do they empower the gut
[0:55] microbes, but also they lose weight,
[0:57] they're less likely to die of heart
[0:59] disease, less likely to be diagnosed
[1:00] with multiple different types of cancer.
[1:02] No way. Yes. What about alcohol?
[1:04] The science is clear. When we drink to
[1:05] the point of having a hangover, is that
[1:07] dehydration? Absolutely not. The issue
[1:09] is you have caused significant damage to
[1:11] your microbiome. But the gut is
[1:13] forgiving, and the choices that you make
[1:15] today, within 24 hours, will have an
[1:17] effect on your microbiome. I want people
[1:19] to eat a diet where they can eat as much
[1:21] as they want without restriction and
[1:23] still achieve their weight goals. And
[1:25] this is completely possible by consuming
[1:27] a diet that's
[1:29] Quick one. This is really, really
[1:30] fascinating to me. On the back end of
[1:32] our YouTube channel, it says that 69.9%
[1:36] of you that watch this channel
[1:37] frequently, over the lifetime of this
[1:39] channel, haven't yet hit the subscribe
[1:40] button. I just wanted to ask you a
[1:42] favor. It helps this channel so much if
[1:44] you choose to just subscribe. Helps us
[1:46] scale the guests, helps us scale the
[1:47] production, and it makes the show
[1:49] bigger. So, if I could ask you for one
[1:51] favor, if you've watched this show
[1:52] before and you've enjoyed it and you
[1:53] like this episode that you're currently
[1:54] watching, could you please hit the
[1:56] subscribe button? Thank you so much, and
[1:58] I will repay that gesture by making sure
[2:01] that everything we do here gets better
[2:02] and better and better and better. That
[2:03] is a promise I'm willing to make you. Do
[2:05] we have a deal?
[2:13] Dr. Will,
[2:14] if someone's just clicked on this
[2:15] conversation and they've they're
[2:17] deciding whether to listen or not, what
[2:18] would be the pitch to those people?
[2:20] What's the benefit if they stick around?
[2:22] Welcome to a what I sincerely believe
[2:25] will be a life-transforming conversation
[2:26] for you. Because the issue is that we
[2:29] are currently living through an epidemic
[2:31] of gut of gut health issues.
[2:33] If we look across the board, this is
[2:35] everywhere. And it's not just, you know,
[2:38] digestion. This is so much more than
[2:40] that. We need this now more than ever.
[2:42] Because ultimately, if we want to be
[2:44] healthy humans, which to me is one of
[2:45] the highest goals that we should hold
[2:47] for ourselves, if we want to be healthy
[2:49] humans, we we absolutely need a healthy
[2:52] gut microbiome in order to accomplish
[2:53] that.
[2:54] What's your sort of academic
[2:55] professional background?
[2:57] Oh gosh, where do we begin?
[2:59] Um So,
[3:01] uh I graduated from Vanderbilt
[3:02] University
[3:04] with a chemistry degree. That was my
[3:06] college, and um I went to Georgetown,
[3:08] which is one of the top medical schools
[3:10] in the country. I
[3:12] spent 3 years at Northwestern as a as
[3:15] internal medicine resident. I won the
[3:17] highest award that they give while
[3:19] there. Then I was the chief medical
[3:21] resident, and I spent 4 years training
[3:24] as both a gastroenterologist in the
[3:26] hospital and also working on clinical
[3:28] research. So,
[3:30] I didn't expect, when I finished all
[3:32] this, that I would be continuing to
[3:34] publish papers at any point in my life
[3:36] in the future. But now, in my work with
[3:39] Zoe as their US medical director, I've
[3:40] been heavily involved in clinical
[3:41] research again. You mentioned a big G
[3:43] word there. Gastroenterologist.
[3:47] Yeah. What is that?
[3:49] Uh we are the specialists in terms of
[3:52] basically like the intestines, the gut.
[3:54] So, if I were to summarize it, I would
[3:56] say guts and butts. Guts and butts.
[3:58] Yeah.
[3:59] The conversation around the gut
[4:01] microbiome and the gut generally has
[4:02] exploded, really since what, 2000 and
[4:05] what, 2006, 2007 time?
[4:08] Before then, I mean, to be fair with
[4:10] you, I think
[4:11] as far as I'm aware, and I'm not that
[4:13] close to doctors or hospitals or
[4:15] research, I've only started hearing
[4:17] about the gut microbiome
[4:18] in the prevalence that I have in the
[4:20] last
[4:21] 2 years? Yeah. 3 years? What is the
[4:24] central misconception that most people
[4:26] have as it relates to their health? That
[4:27] guy that looks into the mirror and goes,
[4:29] "I don't like what I see here. I don't
[4:31] feel good." That's cold, they're they're
[4:33] bloated, they've got gut pains.
[4:35] The current sort of line of thinking
[4:37] will say it is X,
[4:40] but there's something that you believe
[4:41] it is.
[4:42] What is that?
[4:44] Well, I think that all these things
[4:46] ultimately connect back to our gut
[4:48] microbiome, and I think that's the piece
[4:49] of the puzzle that's been missing this
[4:51] entire time. You know, there's it was
[4:52] sort of this black box. If you eat well,
[4:55] you will improve your health. If you do
[4:57] this, you will improve your health. Um
[5:00] what we were missing was the
[5:01] understanding that all of those choices
[5:03] ultimately impact these gut microbes,
[5:05] and by impacting these gut microbes, you
[5:07] can actually transform the physiology
[5:09] within your body.
[5:10] Gut microbes. Yeah. What is that?
[5:13] Gut microbes is my nerdy way of talking
[5:15] about these microorganisms that like
[5:18] you can't see them right now, but
[5:20] they're there. They're, you know, if you
[5:22] hold up your thumb, literally on your
[5:25] thumb, there are as many microbes as
[5:27] there are people in the UK.
[5:29] Really?
[5:29] And they cover our entire body from the
[5:31] top of our head to the tip of our toes.
[5:33] Every single external part of our body
[5:35] is covered with these microbes, but the
[5:37] main spot is actually deep inside of us,
[5:40] which is our colon, the large intestine.
[5:43] In that spot, you can find 38 trillion.
[5:47] Now, these, when I say microbes, it's
[5:49] referring to the fact that they're
[5:50] microscopic and they're alive.
[5:52] It's mostly bacteria.
[5:54] Um in addition to bacteria, could also
[5:56] be fungi,
[5:57] could be parasites, could be viruses.
[6:01] But we have 38 trillion of these, mostly
[6:03] bacteria, focused and concentrated
[6:05] within our colon. So, when we talk about
[6:07] the gut microbiome, we're really
[6:08] referring to them. How did they get
[6:09] there? So, you started in your mother's
[6:12] womb. Mhm. And evidence these days would
[6:15] suggest that you're already starting to
[6:17] come into contact with these microbes,
[6:19] Mhm. but um but for the most part, you
[6:22] haven't really met them yet.
[6:25] Until the water breaks.
[6:27] And in that moment, for the first time,
[6:29] you are exposed to the world.
[6:31] And the world is covered in microbes.
[6:33] Everything that's alive, everything,
[6:36] has a microbiome.
[6:38] Could be a plant, could be an animal,
[6:39] could be an insect, could be us. So,
[6:42] when mom's water breaks, these microbes
[6:44] then enter into the uterus, and you meet
[6:47] them for the first time. But you are
[6:48] particularly exposed to them as you pass
[6:51] through the birth canal.
[6:53] And this is basically like nature's way
[6:55] of being like, "Hello, welcome to the
[6:57] world, and meet your partners.
[7:00] They'll be with you for the rest of your
[7:01] life.
[7:03] And they're here to help you.
[7:04] And they will make you healthier, and
[7:05] this is the result of coevolution that
[7:09] goes back over a billion years. We have
[7:11] been evolving, and which is crazy,
[7:13] because humans
[7:15] have only existed for three three or
[7:16] four million years.
[7:19] But these microbes were the first life
[7:21] on the planet,
[7:22] and all life evolved with these
[7:25] microbes. And things like, for example,
[7:27] our immune system is the product of
[7:29] evolution that started a billion years
[7:32] before humans even existed. We always
[7:34] think of ourselves as one organism, but
[7:36] you're making the case that I'm maybe 36
[7:38] trillion, or whatever you said,
[7:39] organisms in one.
[7:41] And we would call you a superorganism.
[7:44] And that sounds like a Marvel character,
[7:46] which is cool, and we'll take that. But
[7:48] that's actually completely true, because
[7:49] the issue is that if we withdrew these
[7:51] microbes from you,
[7:53] if you were, like, hypothetically, you
[7:55] know, we could talk about the bubble boy
[7:57] from
[7:58] the 1970s, where they actually did this.
[8:01] They tried to have a child live in a
[8:03] sterile world,
[8:04] because he had a specific immune
[8:06] deficiency. So, their thought was if we
[8:08] keep him separate from all the bacteria,
[8:11] then he'll never have a problem. But the
[8:13] issue is that there are consequences.
[8:14] There are consequences to living without
[8:16] microbes, because we need them.
[8:19] So, and through this process of
[8:20] coevolution,
[8:22] literally from the very first human,
[8:24] we grew to trust them.
[8:27] And we trusted them with things that are
[8:28] critically important to us and our
[8:30] success as humans.
[8:32] And we allowed them to integrate into
[8:34] our physiology in a way where, once
[8:35] again, if we don't have them, we're in
[8:37] trouble.
[8:38] And that includes things like digestion,
[8:39] breaking down our food, which to me is
[8:41] like that's the essence of life. Like,
[8:43] you can't get energy into your body
[8:46] without this.
[8:47] And they help us to accomplish that, but
[8:48] they also train our immune system.
[8:51] You know, we talked a moment ago about
[8:53] what happens when you're born, and
[8:54] that's the very beginning of training
[8:56] your immune system. And during those
[8:58] first 3 years of life, it has a massive
[9:00] impact on whether or not you develop
[9:02] allergic issues, autoimmune issues, down
[9:05] the road.
[9:07] They affect our metabolism.
[9:08] Our research at at Zoe has
[9:10] overwhelmingly shown that they play a
[9:12] critical and essential role in
[9:14] controlling, for example, your blood
[9:15] sugar,
[9:16] your blood fat response after a meal.
[9:19] They affect your mood.
[9:20] Um literally, your energy levels.
[9:24] Uh whether or not you suffer from
[9:26] depression, your cognition, your memory,
[9:28] your ability to focus.
[9:30] All affected by these microbes.
[9:32] They affect our hormones. So, in women,
[9:35] conditions like endometriosis,
[9:37] polycystic ovary syndrome, associated
[9:40] with damage to the gut microbiome. In
[9:41] men,
[9:42] erectile dysfunction,
[9:44] which, I mean, to be honest, is not
[9:45] talked about enough.
[9:47] Um
[9:48] perhaps because we've stigmatized this,
[9:50] but the the guys that have this issue,
[9:52] this is like the most important issue to
[9:54] them.
[9:55] And so, when you think about all these
[9:57] things, whether it be
[9:58] digestion, our immune system, our
[10:00] metabolism, our hormones, our mood, our
[10:02] brain health,
[10:04] like to me, this is um
[10:07] uh an overview of everything that
[10:09] matters for human health from my
[10:10] perspective as a medical doctor.
[10:13] And is my gut microbiome different to
[10:15] yours?
[10:16] Uh or do we all have different sort of
[10:18] jungles inside of us?
[10:20] We are all different. And this is one of
[10:23] the things that makes us actually
[10:24] profoundly different. So, to be honest,
[10:26] it's it's this is mind-blowing. If we
[10:29] looked at your genetic code Mhm. and my
[10:31] genetic code,
[10:33] even though clearly we are different
[10:34] people,
[10:35] we our genetic code would be 99.99%
[10:39] the same.
[10:41] It's a small part of our genetics that
[10:44] is different between us as humans.
[10:47] But our microbiome, these 38 trillion
[10:49] microbes that are living inside of us,
[10:52] they can be completely different. So, as
[10:54] a as a classic example, let's pretend
[10:56] that you have an identical twin brother.
[10:58] Identical twin brother. Mhm. All right,
[11:00] so you share the exact same genetic
[11:01] code, you share the same mother. For the
[11:03] vast majority of cases, you would have
[11:05] shared the same childhood and largely
[11:06] the same upbringing and food and things
[11:08] like this.
[11:09] And our research shows that only about
[11:11] 25% of your microbes would be shared,
[11:13] even though you come from the exact same
[11:14] place. You would be 75% or more
[11:17] different. So, you and I,
[11:19] it's hard to say exactly. Like if our
[11:21] diet was, you know, quite similar, then
[11:23] we would have a more similar microbiome,
[11:25] but it still would be more different
[11:27] than the same.
[11:27] And how much then So, I've got a twin,
[11:29] we've got completely different micro gut
[11:31] microbiomes, these sort of um
[11:34] microbes that live inside our bodies.
[11:36] How much of our microbiome
[11:38] can be associated back to disease and
[11:42] things like that in your view? What
[11:44] percentage of disease do you think links
[11:45] back to the gut microbiome?
[11:48] Well, it's hard to say globally, right?
[11:51] It's hard to give an exact number. Um
[11:54] you would have to I think go condition
[11:55] by condition to say.
[11:57] But what I would say is this, my you
[12:00] know, the reason that I became very
[12:01] interested in this as a
[12:02] gastroenterologist
[12:04] is that I was convinced,
[12:06] and I continue to believe this to be
[12:08] true,
[12:09] that every person that walked through
[12:10] the door to see me
[12:12] had a gut microbiome problem.
[12:14] Right? People with irritable bowel
[12:16] syndrome, Crohn's disease, ulcerative
[12:17] colitis, celiac disease, acid reflux, go
[12:21] down the line.
[12:22] Every single one of these, when we study
[12:24] them, we discover that they have got
[12:25] issues.
[12:26] But the other thing, if you expand that,
[12:28] one of the things that I would always
[12:29] do,
[12:30] you know, I'm about to go see a patient.
[12:32] I'm going to walk into the room, and you
[12:33] take the chart off the door, right? You
[12:34] hear if you're the patient, you hear
[12:36] that. You're in the room, and you hear
[12:37] the chart come off the door.
[12:39] And the doctor flips it open, and what
[12:40] do I do?
[12:41] I take a look at their medical history.
[12:44] And when you when you look, what you see
[12:47] is a laundry list of conditions that
[12:49] have been associated with damage to the
[12:51] gut microbiome. So, they're here to see
[12:53] me for their digestive problem, like
[12:55] irritable bowel syndrome.
[12:56] But when I take a look, I see that they
[12:58] have hyperlipidemia, high blood
[13:00] pressure, type 2 diabetes, history of
[13:03] major depression. Uh they may have uh
[13:05] autoimmune condition.
[13:07] Right? So, and then it starts to
[13:08] implicate these different systems that
[13:10] like we have not classically associated
[13:13] immune like autoimmune issues or
[13:15] metabolic issues or cognitive issues or
[13:18] mood issues. We haven't classically
[13:20] associated those things with the gut
[13:21] microbiome, yet they are.
[13:23] And so, to me, do I need like for that
[13:25] particular patient, do I need a poop
[13:27] test to tell me that they have a damaged
[13:29] gut? Absolutely not. It's already clear.
[13:32] And what's the relationship between our
[13:33] gut microbiome and our immune system? I
[13:36] was reading in your the introduction to
[13:37] your book that 70% of the immune system
[13:39] is is the gut. Yeah.
[13:42] The um
[13:44] the walls of your intestine
[13:46] are actually the home of your immune
[13:48] system.
[13:50] We classically would think of the bone
[13:52] marrow as being the place where the
[13:54] immune system exists. That's not true.
[13:55] That's where the immune the immune cells
[13:57] are born there.
[13:58] But then they basically emigrate out,
[14:00] and then they take up residence and live
[14:02] within the walls of your intestine. And
[14:04] by the way, this makes complete sense
[14:07] from an evolutionary perspective because
[14:09] our gut is actually the most of
[14:11] vulnerable part of our body.
[14:13] This is where we come into contact with
[14:14] the outside world. Your skin, you may
[14:16] think of that. No, your skin is a wall.
[14:19] Your gut is the place where actually you
[14:20] are making decisions. Do I absorb and
[14:22] allow this into the body,
[14:24] or do I reject and keep it outside?
[14:27] And in order to help facilitate that,
[14:29] yes, we need our immune system there.
[14:31] But the other thing that we need is we
[14:32] need a barrier.
[14:33] We need something to basically um
[14:36] uh section off the inside of the
[14:38] intestines and keep things separate.
[14:40] So, what we have is called the
[14:42] epithelial layer. And this is quite
[14:45] humble.
[14:46] Like given how important this is in our
[14:47] body,
[14:48] it is just a single layer of cells
[14:51] that are being held together by this
[14:53] kind of cement called tight junctions.
[14:56] They stick together. On one side is 70%
[14:59] of your immune system. On the other side
[15:01] are 38 trillion microbes.
[15:03] And when this barrier breaks down,
[15:06] this is how things that are inside your
[15:07] intestines can get access to your body,
[15:10] um get into your bloodstream,
[15:11] potentially cause a whole body
[15:14] infection.
[15:16] And then the immune system is forced to
[15:17] react.
[15:18] And when this is like we have an
[15:20] infection,
[15:21] it's it's really important. We we This
[15:24] is why we have an immune system to
[15:25] protect us in that setting.
[15:27] But what's happening in the 21st
[15:29] century, what started in the 20th
[15:31] century,
[15:33] is chronic inflammation.
[15:35] And chronic inflammation is the result
[15:38] of a broken barrier.
[15:40] When that gut barrier breaks down, now
[15:42] we are giving access to our body to
[15:45] things that aren't supposed to get
[15:46] access. And the result is that the
[15:49] immune system stays perpetually active
[15:51] because it is constantly trying to clear
[15:53] stuff out because the barrier is broken.
[15:57] And for those who are wondering, so, Dr.
[15:58] B, then how do we how do we fix the
[16:00] barrier? Not to put the question into
[16:03] your mouth, Stephen, but
[16:04] Please do. Please do.
[16:06] The answer is the microbes.
[16:08] The answer is the microbes because they
[16:10] are the stewards of the gut barrier.
[16:12] They help to repair it. Every three or
[16:14] four days,
[16:15] you actually completely transform and
[16:17] recreate your gut barrier. So, it's not
[16:19] the one that you were born with, it's
[16:21] the one that you developed in the last
[16:22] three or four days.
[16:23] And you will turn that over. And when it
[16:25] turns over, we need these gut microbes
[16:27] to help us to form a strong gut barrier.
[16:30] So, because it's constantly turning
[16:32] over, this is where the microbes come
[16:33] in, and they're and they're critically
[16:34] important.
[16:36] Again, the microbes, when you when you
[16:37] reference microbes, you're talking about
[16:38] the bacteria, the yeast, the parasites,
[16:39] the viruses that exist in our in our
[16:41] guts. And how long do they live for? You
[16:43] said they turn over in 3 days. Does that
[16:45] mean that they live for 3 days
[16:47] typically? So, the
[16:48] uh the gut barrier
[16:50] turns over every 3 days. Yeah. Yeah, so
[16:52] and those are human cells. So, those are
[16:54] not the microbes.
[16:55] Okay. Okay, so those are your human
[16:56] cells keeping the microbes separate from
[16:59] your immune system and your body. Mhm.
[17:01] Um these microbes, they are um
[17:04] turning over like literally every 20
[17:07] minutes. They die every 20 minutes?
[17:09] So, well, not necessarily dying.
[17:11] Replicating. Replicating. Okay. Right?
[17:13] And so, if we think about this, if we
[17:15] had if you had one microbe
[17:17] in your intestines right now,
[17:20] and we feed it something, whatever it
[17:21] may be, good thing, bad thing, whatever.
[17:24] 24 hours from now, that microbe will
[17:27] have spawned at least a thousand new
[17:29] microbes.
[17:30] So, if you think about the power that
[17:32] exists there to amplify choices,
[17:35] starting with one and ending 24 hours
[17:37] later with a thousand, it's crazy.
[17:39] There's this really interesting sort of
[17:41] reframing in the introduction of your
[17:43] book, which
[17:45] is really simple, but it does cause you
[17:47] to I think it's a really powerful frame
[17:49] to think through about what we and how
[17:50] we eat, which is where you say that um
[17:53] each of us consumes an average of 1.3 kg
[17:56] of food per day. Keeping the math
[17:58] simple, that's 475 kilos of food per
[18:01] year, meaning we'll consume about 36,300
[18:05] kilos of food during our lifetime.
[18:08] And in contrast to the couple of
[18:10] milligrams of medicine that we take,
[18:13] it really makes you realize that food is
[18:15] in fact the medicine that we're feeding
[18:17] our body at all times. We think we sort
[18:19] of compartmentalize food over here as
[18:21] this energy source that quenches hunger,
[18:23] and then we have medicine over here to
[18:24] fix stuff. Yeah. But in fact,
[18:27] you're doing 36,000 kilos of food in
[18:30] your lifetime. So, the the thing that's
[18:32] having the biggest way on your medical,
[18:35] your sort of uh physiological health and
[18:36] your your your gut health is of course
[18:39] the food.
[18:39] The food is the medicine. Well, I think
[18:41] that there's two important takeaways
[18:42] from that cuz there was a study actually
[18:44] that changed my life in 2014 that came
[18:46] out. Um this was published in the
[18:48] journal Nature, which is literally the
[18:49] top journal on the planet. And um uh the
[18:53] author was Warren David from Duke
[18:54] University. And you have to understand,
[18:56] if we go back, this is almost 10 years
[18:58] ago. In this moment, we didn't know if
[19:01] food changed microbes in humans. We
[19:04] didn't know this.
[19:05] This is new information.
[19:07] We knew it in mice, but it's not the
[19:09] same. Mice are not humans.
[19:11] Um so, what they did to try to prove
[19:12] this is they put people on uh
[19:15] diametrically opposed diets.
[19:17] So, a completely 100% plant-based diet
[19:19] versus a completely 100% animal-based
[19:21] diet. It was only a 5-day study,
[19:24] which is interesting because within 5
[19:26] days, you can actually see massive
[19:28] results. And the key one of the key
[19:30] takeaways from this study
[19:32] is that the choices that you make today,
[19:35] within 24 hours,
[19:37] will have an effect on your microbiome.
[19:39] In that study, when they changed a
[19:41] person's diet, 24 hours later, you could
[19:44] already see things underway shifting.
[19:48] So, now, the other thing to keep in mind
[19:49] here is that I think is really important
[19:52] is the gut is forgiving.
[19:55] I mean, to a degree, you can only beat
[19:56] it up so much.
[19:58] But the gut is forgiving. So, this
[20:00] doesn't mean that there are foods that
[20:01] are on the table and off the table.
[20:04] Everything is on the table.
[20:06] But what we want is we want to create a
[20:08] weight or a disproportionate consumption
[20:11] of those high-quality foods because when
[20:13] we do, we are lifting these microbes up.
[20:15] Explain that process of food and the
[20:18] impact it has on the microbes. So, is it
[20:21] like watering certain microbes? Is that
[20:23] a way to think about it in simple terms?
[20:25] These microbes are as alive as you and I
[20:27] are, Steven, and we need to eat.
[20:30] Um if I don't eat, I get quite hungry.
[20:32] And they do, too.
[20:34] And but it turns out that the reason
[20:36] that they took up residence, cuz they
[20:37] could have been anywhere. They could
[20:38] have stayed inside soil or lived on a
[20:40] plant or something like that. They chose
[20:43] to live inside of you. And the reason
[20:44] why they are inside your colon is
[20:46] because they get access to nutrition.
[20:48] You do that for them. You go out, you
[20:50] find food, and you deliver that to them.
[20:53] Whatever goes into your mouth, whatever
[20:54] it may be,
[20:55] it will come into contact with these
[20:57] microbes.
[20:58] And they will consume it. And and this
[21:01] becomes their energy source because they
[21:03] are alive, they need energy.
[21:05] So, but the choices that you make
[21:07] impact which microbes get to eat.
[21:11] So, not every single microbe likes kale.
[21:14] Not every single microbe likes sugar.
[21:17] But there are some that like sugar and
[21:19] some that like kale.
[21:20] And when you make these choices,
[21:21] whatever it may be,
[21:24] those choices ultimately are going to
[21:25] feed specific families of microbes, lift
[21:28] them up, and allow them to thrive.
[21:30] So, when we talk about, you know,
[21:32] improving dietary quality, and you hear
[21:34] me talk about this in Fiber Fueled,
[21:36] which is a message that I started
[21:38] sharing publicly back in 2018.
[21:41] Um and the book came out in 2020. Or if
[21:43] you listen to Tim Spector,
[21:45] who published the paper that I'm about
[21:47] to talk about.
[21:49] Um the science is clear.
[21:51] The way to lift the microbes up is by
[21:53] eating a variety of plants.
[21:56] Now, in Tim Spector's paper that
[21:58] originally came out, it's called the
[21:59] American Gut Project. But by the way,
[22:01] the British Gut Project was a massive
[22:03] and critically important part of the
[22:04] study.
[22:05] In that study,
[22:07] um you have to understand the magic
[22:08] number that they came to was 30.
[22:11] A lot of that had to do with just the
[22:13] technique that they were using to
[22:14] measure.
[22:15] It doesn't mean that 29 is bad and 30 is
[22:18] fantastic.
[22:20] It's all on a spectrum. 30? 30 different
[22:23] plants per week. Mhm. Yeah. 30 different
[22:25] plants per week. So, the key is we want
[22:27] varieties of plants, and every single
[22:30] plant choice ultimately is fuel for a
[22:34] healthy gut microbiome. So, that's
[22:35] fruits, vegetables, whole grains, seeds,
[22:37] nuts, and legumes. It's not just
[22:38] veggies, it's not just kale. And to me,
[22:41] like one of the things that I've always
[22:42] tried to do, whether it be as a medical
[22:43] doctor or as an author, I want to meet
[22:46] people where they are.
[22:47] So, like if it were if I were consulting
[22:49] with you, I want to know where you stand
[22:51] right now.
[22:52] And then we're going to set realistic
[22:53] goals. Because so, for a person who's
[22:56] eating 10 different plants per week,
[22:57] which by the way is more than I was
[22:59] eating 10 years ago,
[23:01] to go to 30 instantly, that would be
[23:03] quite hard. And when it's hard, it's
[23:04] more likely to become unsustainable.
[23:07] I would go from 10 to 15. And when you
[23:10] hit 15, I would be celebrating. How many
[23:12] plants does the average person eat in
[23:14] the Western world, America, the UK,
[23:16] Europe?
[23:17] Do you know?
[23:18] Uh I believe in the American Gut
[23:20] Project, the number was around 10 to 15
[23:23] for the average person. It was a
[23:24] minority of people that were hitting 30
[23:26] per week in that study.
[23:28] It's interesting. When I I did my Zoe
[23:30] test, I got my results back, and it did
[23:32] say that I had quite a narrow gut
[23:33] microbiome in comparison to my partner.
[23:37] And I was thinking about this. I was
[23:38] like, you know, whenever we go
[23:39] somewhere, whenever we go to a
[23:40] restaurant, she orders
[23:42] new things Yeah. all the time. And if
[23:45] you look at our fridge, it's like tahini
[23:46] and this and all this like all these
[23:49] plants, especially the top part of our
[23:50] fridge, it's all like fermented stuff.
[23:52] She eats like she's a like a rabbit or
[23:54] something. She just eats anything. And
[23:56] she eats diverse food, and she orders
[23:59] new things, and then there's me. Yeah.
[24:01] I like what I like.
[24:02] And if I go to a restaurant, anyone
[24:04] that's been to a restaurant with me like
[24:05] three times could order for me because
[24:06] they know
[24:07] um until I got my Zoe results back, and
[24:10] it was it was pretty alarming cuz she
[24:12] had her
[24:14] microbes were like a like the Amazon
[24:16] rainforest. Nice. And mine were like,
[24:18] you know, a park at the end of the
[24:19] street. Ugh. You know? I think that it's
[24:22] important to start with food that you
[24:24] like. Yeah. We're all like that, what
[24:26] you described. But the issue is finding
[24:28] that motivation to push yourself. To me,
[24:31] this is the this is the piece of the
[24:33] puzzle. Like again, this was a black
[24:35] box. We didn't know anything about the
[24:36] gut microbiome. We just had like
[24:39] nutritional ideas being tossed at us.
[24:41] Now, this is filling in the gaps where
[24:43] it's like, hold up. No. Nutrition
[24:44] affects the microbes, the microbes
[24:46] affect us as humans. Now, we can connect
[24:48] those dots. And to me, I find this very
[24:50] empowering and motivating to know that
[24:52] that exists and to know that those
[24:54] choices, every single meal, is an
[24:56] opportunity to
[24:57] follow this concept and add more
[24:59] diversity to your plate. But the other
[25:00] thing is you mentioned that your partner
[25:03] is eating fermented food.
[25:04] That's a lost art.
[25:06] People have not been consuming fermented
[25:08] food in the Western world.
[25:10] And the research is quite clear and
[25:12] standing out at this point that actually
[25:14] there um was a fascinating study out of
[25:16] Stanford University,
[25:18] randomized controlled trial. The
[25:20] intervention was to add fermented food
[25:22] to the diet in people that had not been
[25:25] consuming fermented food. And what they
[25:27] found 8 weeks later is that they had
[25:29] increased the diversity within their gut
[25:31] microbiome. What does that mean?
[25:33] If your microbiome is the park at the
[25:35] end of the street,
[25:36] adding fermented food, we can we can
[25:38] make it into a jungle. Give me some
[25:39] examples of fermented foods. And what is
[25:41] the fermented part? Like what does that
[25:43] mean?
[25:44] Well, uh first of all, we we mentioned
[25:46] that all
[25:48] all life on this planet has a
[25:50] microbiome.
[25:51] So, there was an interesting study where
[25:53] they analyzed the microbiome of apples
[25:55] and discovered that when you eat an
[25:57] apple, like you just grab an apple off
[25:59] the uh out of the fruit bowl,
[26:02] um that apple has about 100 million
[26:04] microbes that are a part of it.
[26:06] So, they're already there. And those
[26:08] microbes have been a part of that
[26:09] apple's life, helping it to grow from a
[26:11] flower to a fruit.
[26:13] Okay. So,
[26:14] um now,
[26:16] these microbes, they are also involved
[26:18] in the life cycle of that apple. So,
[26:20] when the apple goes to spoil,
[26:23] the microbes are the ones doing that. In
[26:24] fact, I would argue that when food
[26:26] spoils, I actually find that reassuring.
[26:29] If food doesn't spoil, we should be
[26:31] concerned.
[26:32] The microbes are helping to facilitate
[26:34] that spoilage that takes place, and
[26:36] that's because the Earth is taking it
[26:37] back. It's this it's the cycle of life.
[26:39] It's going to turn into dirt.
[26:41] Right? Now, fermentation is where we
[26:44] actually grab that process,
[26:47] and we control it. Almost like a
[26:48] magician, we're shaping it.
[26:51] And what we're having is we're
[26:52] empowering certain microbes
[26:56] to protect that food so it does not
[26:58] spoil. And they transform it.
[27:01] So, if you were to take cabbage,
[27:04] you know, you don't need to do anything
[27:05] special to this cabbage. You literally
[27:06] just buy cabbage, perhaps at your
[27:08] farmer's market.
[27:10] Chop it up, put it into a mason jar,
[27:12] pack it in there,
[27:14] and add a sea salt brine solution, a
[27:16] salt water solution.
[27:19] And you basically put this into, you
[27:21] know, a nice cool space.
[27:24] Give it a week,
[27:25] you will have sauerkraut.
[27:27] Sauerkraut is not salty cabbage.
[27:30] It's tart. It's bitter.
[27:32] Uh it's acidic.
[27:34] Um it's delicious. When you make it
[27:36] yourself, it is completely different
[27:38] than the sauerkraut that I grew up on
[27:40] that came from a can,
[27:41] which was soft and disgusting.
[27:44] So, this is what fermentation is. It's
[27:46] transformation.
[27:47] The microbes, specifically bacteria and
[27:50] yeasts,
[27:52] are transforming the food for us.
[27:54] And when they do this, they also are
[27:56] eating.
[27:58] So, because they eat, they grow
[28:00] stronger, and they multiply.
[28:02] So, you are creating a food that is high
[28:05] in microbes, which we could call
[28:07] probiotics.
[28:09] It has been transformed to unlock the
[28:11] nutrition,
[28:12] which we could call prebiotics.
[28:14] Prebiotics are the parts of our food
[28:16] that actually feed the microbes inside
[28:19] of us. It's their food, prebiotics.
[28:21] And they are releasing new chemicals
[28:24] that can have beneficial effects on your
[28:26] body, which we call postbiotics.
[28:30] You find all of this in that one jar of
[28:32] sauerkraut.
[28:34] So, that to me is a superfood.
[28:37] And it could be sauerkraut, it could be
[28:39] kimchi.
[28:40] Uh pickles, like pickles are not meant
[28:42] to be a vinegar thing.
[28:44] By the way, vinegar is the product of
[28:47] fermentation.
[28:48] But pickles were never meant to be, hey,
[28:50] add cucumbers and some vinegar and call
[28:51] it a day.
[28:53] Cucumber
[28:54] True pickles are meant to be that you
[28:56] take the cucumbers, you don't skin them,
[28:58] you allow the microbes that are on the
[29:00] surface to do their job, and you put
[29:02] them into a salt water solution with
[29:04] some, you know, some dill, some garlic,
[29:06] black peppercorns, and a couple days
[29:09] later, you will have a pickle.
[29:11] I want to make sure I'm super clear on
[29:12] those three
[29:14] biotics that you mentioned. So,
[29:16] prebiotics are the food for microbes.
[29:20] Probiotics are
[29:22] the microbes themselves.
[29:25] And then postbiotics are the compounds
[29:27] that the microbes make.
[29:30] Is that roughly accurate? That's roughly
[29:32] accurate. And there's a minor caveat,
[29:34] which is that for these things,
[29:36] prebiotic and probiotic,
[29:38] they have to have beneficial effects on
[29:40] humans in order to count. Okay. So, we
[29:44] can't call it a a
[29:45] because it has just an effect on
[29:47] microbes.
[29:48] Sugar has an effect on microbes. It's
[29:51] not a prebiotic. Ah, okay. Okay, so and
[29:53] the same is true for probiotics. Now,
[29:55] the original conception of probiotics
[29:57] that most of us have it comes from a
[29:59] capsule.
[30:00] Right? And the reason why we can call it
[30:02] that is because we have demonstrated
[30:04] through clinical studies that the
[30:06] specific types of bacteria or or yeasts
[30:08] in some cases that you find in that
[30:10] capsule have been proven to be
[30:12] beneficial to humans.
[30:15] So, the prebiotic is a food. The
[30:18] probiotic is actually alive. Yep. And
[30:20] then the postbiotic is not alive. That's
[30:22] a compound that's produced by the things
[30:24] that are alive.
[30:25] That's right. And the key with all of
[30:28] this
[30:30] is the postbiotic.
[30:31] So, one of the And And these can be
[30:33] things that are completely beneficial
[30:35] and good to us as humans. An example of
[30:37] this are the short-chain fatty acids.
[30:39] Short-chain fatty acids are the product
[30:43] of consuming fiber or resistant
[30:45] starches.
[30:46] And they come into contact with your
[30:48] microbes. Again, you would not be able
[30:50] to get these if you were sterile.
[30:53] Can't I just drink them in a can?
[30:54] Postbiotics. Is there not a can of
[30:56] postbiotics that I can just drink?
[30:58] Well, so they're coming out now with
[30:59] supplements that um are these
[31:01] postbiotics in some cases. Mhm. Okay.
[31:04] And uh the issue that I've taken with
[31:06] them and I've actually discussed with
[31:08] some people within the supplement
[31:09] industry
[31:10] let's not assume that that's going to do
[31:13] the exact same thing that eating a
[31:15] high-fiber diet is going to do.
[31:18] It's not the same. So, let's then talk
[31:19] about what happens with those
[31:22] I'm assuming that the postbiotics um
[31:25] compounds are the things that have the
[31:26] help all the health benefits. So, the
[31:28] reason why the gut microbiome is so
[31:30] healthy, the reason why these microbes
[31:31] are so beneficial is because they
[31:33] produce postbiotics. And these
[31:35] postbiotics help our body in various
[31:36] ways. Yes. So, we uh
[31:39] mentioned earlier we were discussing how
[31:41] we have this gut barrier that's key to
[31:44] protecting our immune system.
[31:46] And I mentioned that the the microbes
[31:48] are the stewards
[31:50] of that of that barrier.
[31:52] It's the postbiotics.
[31:54] It's the short-chain fatty acids.
[31:56] Butyrate, acetate, propionate
[31:59] that are produced by these bacteria that
[32:02] builds the wall.
[32:04] When you want to build your wall and
[32:06] protect your body and reduce
[32:08] inflammation
[32:09] you need more of this.
[32:12] Now, it's not That's not the only thing
[32:13] that they do. Those postbiotic
[32:15] short-chain fatty acids also directly
[32:17] affect your immune system.
[32:19] Directly affect your metabolism.
[32:21] Cross the Get into your bloodstream.
[32:24] Pass throughout your entire body. Cross
[32:26] the blood-brain barrier.
[32:28] They have the ability to actually get
[32:29] access to your brain
[32:32] and can affect your brain. And we could
[32:34] talk about different ways that that they
[32:36] can do that.
[32:37] But the point is that this is what um
[32:40] really matters because the microbes
[32:42] produce these short-chain fatty acids
[32:44] and these short-chain fatty acids have
[32:46] healing effects throughout the entire
[32:48] body. And when we when we see human
[32:51] studies looking at fiber consumption
[32:54] and showing us how beneficial fiber is
[32:56] to us as humans
[32:57] the reason I want everyone to understand
[32:59] the reason why fiber is beneficial to us
[33:02] as humans is because
[33:04] fiber comes into contact with microbes
[33:06] and those microbes release short-chain
[33:07] fatty acids. That's what's happening.
[33:10] Metabolism.
[33:12] Metabolism is the I've been learning a
[33:13] little bit about metabolism recently.
[33:15] When people think of metabolism, they
[33:16] think of the speed in which I process my
[33:19] food. So, people in society say I've got
[33:21] a high metabolism, which means they're
[33:23] probably going to be quite skinny. A low
[33:24] metabolism means, you know, I'm probably
[33:26] going to take longer to process my food.
[33:28] What is the role between the
[33:29] relationship between my gut and my
[33:31] metabolism? And have I defined I've
[33:33] probably defined metabolism wrong there,
[33:35] but
[33:36] what is the relationship?
[33:38] Well, metabolism is basically dealing
[33:39] with the currency of energy. Right? So,
[33:42] And it's the engine that drives us as
[33:43] humans.
[33:45] And so, how do these microbes affect our
[33:48] metabolism? Well, we have uh
[33:50] researchers at Zoe looking at this
[33:51] directly
[33:53] called the Predict One study.
[33:55] And in that we were looking at like what
[33:57] is the thing that tells me predicts
[34:01] what your blood sugar response is going
[34:02] to be to this food
[34:04] or your blood fat response after a meal.
[34:07] And when you start to line these things
[34:09] up, they're individually different.
[34:10] They're not the same.
[34:12] But if you look at both of them the gut
[34:14] microbiome plays an essential and
[34:15] critical role in each.
[34:18] So, in other words, if we know what your
[34:20] gut microbes are
[34:21] then that empowers us to be able to
[34:23] understand
[34:25] why you have high blood sugar, why you
[34:27] have low blood sugar.
[34:28] Now, if we want to get super nerdy and
[34:30] detailed into the weeds a little bit of
[34:33] how this is actually happening, it does
[34:35] come back in many ways to these
[34:36] short-chain fatty acids. They're not the
[34:39] only thing. We're, you know, in some
[34:40] ways we're reducing it a little bit too
[34:42] much. So, I just want to be clear to
[34:44] everyone. There's other things going on,
[34:46] too. But these short-chain fatty acids,
[34:48] they have the ability to basically
[34:49] activate certain receptors in cells that
[34:52] will basically like allow us to have
[34:54] more sensitivity to insulin, to reduce
[34:57] fat storage, to enhance fat burning. So,
[35:00] at the end of the day when we think
[35:01] about these sort of measures of
[35:02] metabolism cuz there's certain things.
[35:05] Blood sugar response.
[35:07] Blood fat. Cholesterol levels.
[35:09] Um
[35:11] uh visceral obe- visceral adiposity
[35:13] meaning meaning like fat that exists
[35:15] around our stomach.
[35:18] When you look at all these things, the
[35:19] gut microbes play an essential role in
[35:21] regulating every single one of them. And
[35:23] the short-chain fatty acids tend to be
[35:24] the key. I I read in your book that 60%
[35:27] of poop is bacteria. Yeah.
[35:30] Which it just blew my mind. Yeah, and I
[35:32] think that this is an important
[35:33] conversation to have because we have
[35:35] stigmatized poop. We're not allowed to
[35:37] look in the bowl.
[35:38] We should be looking in the bowl.
[35:41] And the reason why is because if I were
[35:42] a cardiologist
[35:44] I would come over and I would check your
[35:45] pulse.
[35:47] I would listen to your heart. And those
[35:49] vital signs would allow me to have an
[35:51] idea of how you're doing in terms of
[35:53] like just on a basic level, your
[35:54] cardiovascular health.
[35:56] All right? I'm a gastroenterologist. If
[35:58] I want to know the basics of what's
[36:00] going on with you in your body, I want I
[36:02] need to know how you're pooping.
[36:04] And what your poop looks like because
[36:07] 60% of it is
[36:09] microbial in origin.
[36:11] Because it is not just the excrement of
[36:13] your food. What your poop looks like
[36:17] allows me to have insights into your gut
[36:19] health.
[36:20] And we've actually proven this. We've
[36:21] actually proven this at Zoe because what
[36:23] we found we did a study called um
[36:27] blue poo.
[36:28] And we fed people blue muffins. It had a
[36:32] blue food dye.
[36:34] And basically it's quite simple. You eat
[36:36] the muffins
[36:38] and then you wait to see when they show
[36:39] up in the toilet bowl.
[36:41] And based upon that time, which is
[36:43] basically your gut transit time, how
[36:44] long it takes for the blue dye
[36:47] to pass through your intestines
[36:49] we could tell you um
[36:52] what's going on with your gut
[36:52] microbiome.
[36:55] We could talk about cardiovascular risk.
[36:58] We could talk about visceral fat.
[37:00] All quite simply tied to your gut
[37:03] transit time based upon eating a blue
[37:06] muffin.
[37:07] So, these things Many of these um things
[37:10] that you and I are discussing today,
[37:11] whether it be the gut connecting to our
[37:13] metabolism, our immune system, or
[37:14] whatever it may be
[37:16] we can connect them back to these simple
[37:19] measures like what does your poop look
[37:21] like?
[37:22] Or
[37:23] um
[37:24] or how long does it take for you to have
[37:26] a bowel movement?
[37:27] The gut transit time. That's super
[37:29] fascinating. I do want to talk about
[37:30] poop as well, but um the gut transit
[37:32] time.
[37:33] Yeah. That's the time it takes for a
[37:34] muffin to go from my lips to the toilet
[37:37] bowl. Yes. And is a high gut transit
[37:40] time better than a low one? And what is
[37:41] determining whether I have a high gut a
[37:44] good gut transit time or a not so good
[37:46] one? Yeah. So, gut transit time is a um
[37:50] uh
[37:51] a personal measure of the health of this
[37:53] entire digestive system.
[37:55] The reason why you do the blue dye, by
[37:58] the way, instead of like eating beets or
[38:00] something like that is that the blue dye
[38:02] we have like clinically validated this.
[38:05] So, this this paper was published in the
[38:07] journal Gut, which is the top European
[38:08] gastroenterology journal.
[38:11] And there's a couple of specific time
[38:13] points that we can use to sort of cut
[38:14] off these measures.
[38:17] Um the first is 14 hours. If you are
[38:19] less than 14 hours, that is very fast.
[38:22] The other is 58 hours. If you are more
[38:25] than 58 hours, that's very slow.
[38:29] All right? So, you eat these muffins and
[38:31] then you basically just record when did
[38:33] they show up?
[38:34] And the average person is somewhere on
[38:36] the range of 24 hours
[38:39] or 48 hours. Typically 1 or 2 days after
[38:41] eating the muffins, that's when you you
[38:43] start to see this. And those are both
[38:44] considered to be normal.
[38:46] Now, if we were to break these things in
[38:48] out into less than 14 hours, more than
[38:51] 58 hours, or you know, these two sort of
[38:54] peaks at 24 and 48 what you start to see
[38:57] is that this is four groups and these
[38:59] four groups every single one of them is
[39:00] a little bit different in terms of their
[39:01] gut microbiome.
[39:03] A little bit different in terms of their
[39:04] gut diversity.
[39:06] And we can make associations between
[39:08] these things and what people are eating.
[39:11] So, the high-fiber consumers are all
[39:14] showing up in the middle which means
[39:16] normal.
[39:17] And the low-fiber consumers are the
[39:19] people that are showing up on the
[39:20] outside.
[39:21] And it brings us to one of the
[39:22] properties of fiber that's kind of
[39:24] fascinating which is that whether you
[39:26] have diarrhea or constipation there's
[39:28] only one thing that can correct both of
[39:30] those.
[39:31] Diarrhea and constipation are both fixed
[39:34] with dietary fiber. It helps to
[39:36] normalize our stool, bring it back to
[39:37] the middle. So, in a perfect world,
[39:39] where do we you to be? We want to
[39:41] generally be pooping about once a day.
[39:44] So, you want your gut transit time to be
[39:45] about 24 hours or less.
[39:48] Um that being said, like is a person
[39:51] unhealthy if it takes 2 days for this to
[39:53] show up in their poop? No, I wouldn't
[39:54] characterize them as being unhealthy.
[39:56] But I I do think that this is one of the
[39:58] things that we can look at that's
[40:00] simple, it's it's nearly free, and um
[40:03] available all of us to try at home.
[40:05] So, yeah, so you you you would have said
[40:07] that if someone's going to the toilet,
[40:08] you know, three or four times a day or
[40:10] more, then there's probably a fiber
[40:12] problem. There's may well be a fiber
[40:14] problem. And if they're
[40:16] you know, they're sort of chronically
[40:18] constipated,
[40:19] it's also probably a fiber problem at
[40:21] the heart of it.
[40:22] Generally speaking, yes. Now, I will say
[40:24] that fiber is not as simple as I wish
[40:28] that it was, and and the reason why I
[40:30] bring that up is that for a person who's
[40:34] low on their fiber consumption,
[40:36] um and they may suffer with these
[40:38] issues,
[40:39] increasing fiber is hard for them.
[40:43] And many people don't feel well if they
[40:45] go too hard too fast when they do this.
[40:49] It folds them over. They feel unwell. I
[40:51] was in the exact same spot 10 years ago.
[40:53] If I tried to eat like, you know, chili
[40:55] with a bunch of beans, I was not happy.
[40:57] So, I preferred to stay away from that.
[41:00] So, the point that I'm trying to make
[41:01] about this, the reason why people
[41:03] struggle with fiber, is because we are
[41:06] 100% reliant
[41:08] on our gut microbes to digest our fiber
[41:10] for us.
[41:12] We don't have the enzymes to break them
[41:13] down to break down fiber.
[41:16] The gut microbes are doing it. So, if
[41:17] you have a damaged microbiome,
[41:20] and you never eat fiber,
[41:22] you're you can't expect your microbes to
[41:24] be good at digesting fiber. Our
[41:26] microbes, they learn and they get good
[41:29] at the stuff that we allow them to
[41:30] practice.
[41:32] So, when we start to add more fiber, the
[41:33] way that I had recommend to people do
[41:35] this
[41:36] is to start low and go slow. That just
[41:38] means adding a little bit at a time,
[41:40] slowly over over the course of at least
[41:43] weeks, if not months.
[41:45] Um and this is what allows your your gut
[41:47] microbes basically to keep up and adjust
[41:49] to what you're doing. What about fecal
[41:51] treatment? You said that that if our gut
[41:53] microbiome is damaged, um it's not going
[41:55] to be great at processing the fiber. So,
[41:58] can't I just get someone's poop who has,
[42:01] you know, that 60% of their poop is the
[42:04] the microbes,
[42:05] and eat it?
[42:06] Or do some kind of fecal treatment where
[42:08] I put it in my body?
[42:10] So, this is this is actually being done.
[42:13] Um now, we've been doing fecal
[42:15] transplants where we would take from a
[42:17] donor
[42:19] and put it into a person for an
[42:21] infection called C. diff.
[42:24] And we've been doing this for more than
[42:25] 10 years.
[42:27] And it is fascinating.
[42:29] The studies with fecal transplants in
[42:31] humans
[42:33] have not been
[42:35] um
[42:36] as successful
[42:38] as they were for the C. diff.
[42:41] So, we would love to say that we could
[42:43] treat ulcerative colitis,
[42:46] which is inflammatory bowel disease,
[42:48] with a fecal transplant.
[42:50] Um
[42:51] generally,
[42:52] it seems that we cannot, at least where
[42:54] we stand today.
[42:56] But there is something that interesting
[42:58] that we found in one of the studies on
[43:00] this topic, which is that there was one
[43:03] study where, again, these studies are
[43:04] small. Like, we need bigger studies to
[43:06] really fully understand this.
[43:08] There was one study where
[43:10] they did have a couple of people on with
[43:12] ulcerative colitis who went into
[43:13] remission, meaning that their disease
[43:15] was no longer active
[43:17] after a fecal transplant.
[43:19] And they asked the question, what was
[43:20] unique?
[43:22] And they found they all had the same
[43:23] donor.
[43:26] So,
[43:27] what we think is that there's probably
[43:30] specific donors
[43:32] for specific diseases
[43:34] that could actually potentially fix
[43:36] those issues because at their root, they
[43:38] are gut issues.
[43:40] I think that the future of fecal
[43:41] transplant is very promising.
[43:44] But the complexity of figuring out who
[43:46] are these donors, like could I be a good
[43:48] donor for some specific disease that I
[43:50] don't even have myself, and don't know
[43:52] anything about?
[43:53] Possibly. And this is what we have to
[43:55] figure out.
[43:56] And how do these poop transplants
[43:58] happen?
[43:59] Is it orally or is it
[44:01] some other way? Are they injecting this
[44:03] poop? Are they putting it up their butt?
[44:04] What are they doing with it?
[44:05] There's a couple ways. So, the classic
[44:08] is a colonoscopy.
[44:09] So, the way that I always I would always
[44:11] administer it is that the patient comes
[44:13] in for a colonoscopy. They're completely
[44:15] asleep. They're not aware of anything
[44:17] that's happening. And during the
[44:18] procedure, I basically release this
[44:20] stuff. It's a liquid. It's not as gross
[44:22] as it sounds.
[44:23] So, that's a tube up the butt. The
[44:25] colonoscopy? Yeah. That's a tube up the
[44:26] butt. Okay. Yeah, that's a tube up the
[44:28] butt. Now, the new technology that's
[44:30] been emerging in the last few years is
[44:32] that they can actually dry out the
[44:34] stool, so they lyophilize it, and put it
[44:36] into capsules.
[44:38] You have to take a ton of capsules in
[44:39] order to do this. But this is an
[44:42] alternative choice. It's like you could
[44:43] start taking this. What I think would be
[44:45] interesting
[44:47] Well, hopefully not.
[44:49] Do you know what I mean? I've had a
[44:50] couple of mega omega-3 capsules break,
[44:52] and it's a nightmare. So, Oh, dear.
[44:54] Yeah. This is not where we want to be.
[44:57] Um
[44:58] what what we're transitioning towards,
[45:01] like the past was this big event. You
[45:04] had to come in, get a big procedure,
[45:06] colonoscopy. Well, to do that repeatedly
[45:09] is simply not sustainable. That's not
[45:10] realistic.
[45:12] Now, what we're entering into is the
[45:13] possibility that you could do this every
[45:14] day.
[45:15] You could just take your poop capsule
[45:16] every single day. God, I'd love to be
[45:18] the CEO of that company.
[45:20] That would be so fun.
[45:22] I mean, I think that I think that this
[45:24] is going to happen. We just need Yeah,
[45:25] but I think we need the the technology
[45:27] is there.
[45:28] The technology is there. So, what do we
[45:30] need? We need to identify who are the
[45:32] proper donors for this.
[45:34] And we need to run the clinical trials
[45:37] to prove that it will work. But to me,
[45:38] this is a super probiotic. Cuz it's not
[45:41] just, you know, most probiotics are just
[45:43] one single strain. Um and they can be
[45:45] beneficial. I'm not disparaging
[45:47] probiotics in any way. They can
[45:48] definitely be beneficial. But what we're
[45:50] talking about is a new future where
[45:51] you're actually
[45:53] reconstituting a healthy microbiome. And
[45:56] Steven, on this topic, real quick,
[45:58] it is fascinating because some of the
[46:00] people who are in this space,
[46:03] they're worried about the way the world
[46:05] is going in terms of microbes.
[46:07] Right? So, there's been this concept
[46:09] that perhaps you've heard about where
[46:11] which is that um
[46:13] there's like been this great uh
[46:15] extinction event that's taken place.
[46:18] Right? Where many species of animals are
[46:21] dying. And
[46:23] um and they're gone.
[46:25] Microbial scientists are worried cuz the
[46:27] same thing is happening on a microbial
[46:29] level.
[46:30] So, if you were to compare our
[46:32] microbiome as Westerners
[46:34] to a person who lives in a more uh
[46:37] primitive environment in Africa,
[46:39] we have half the microbes that they do.
[46:43] And so, what these scientists are doing
[46:44] is they're saying,
[46:46] "What if those microbes that you find in
[46:49] those people,
[46:51] what if we need them? What if we evolved
[46:53] and they're required for us?" So,
[46:55] they're creating a bank where they're
[46:57] collecting these poop samples from like
[47:00] pr- uh primitive tribal people,
[47:03] and saving them
[47:05] in the event that it turns out that the
[47:06] only way back
[47:09] is to actually take the poop from these
[47:11] people and create super probiotics that
[47:14] would help to reconstitute our
[47:15] microbiome.
[47:16] I'm so compelled by this whole idea that
[47:18] there's going to be this range of
[47:19] supplements in the future that are just
[47:21] like poop capsules.
[47:21] I don't think it'll be supplements,
[47:22] though. I think it'll be completely
[47:23] regulated. Well, what I mean by that is
[47:25] there's a difference in regulation
[47:26] between supplements
[47:28] and um pharmaceuticals. And I don't
[47:30] think they'll have any choice but to
[47:32] regulate this on the same level that you
[47:34] would a drug. Cuz in my head I have this
[47:35] idea of, you know, if this really takes
[47:38] off,
[47:39] people with great poop are going to be,
[47:41] you know, expensive. Dude, I think my
[47:43] stock is rising. Yeah, how much is your
[47:45] poop?
[47:47] All right. If you want my poop, you will
[47:48] have to pay for it.
[47:50] But it's going to be expensive. If you
[47:51] only go to the cuz you're healthy, you
[47:52] go to the toilet once a day, it's going
[47:54] to be like gold.
[47:56] Um and that's the fascinating thing.
[47:57] Poop is on the biggest comeback in the
[47:59] history of comebacks right now. Maybe
[48:01] maybe that's where we live in a post AI
[48:03] world. Maybe that's the currency we
[48:05] trade in. You know what I'm saying? Cuz
[48:07] we're going to have lit- little else to
[48:08] do. So,
[48:09] I you know, gosh, that is a dark uh
[48:12] disturbing vision for the future, but I
[48:14] could see where I could see where that's
[48:16] possible. I mean, I I do think like it's
[48:18] fascinating to consider that what what
[48:20] we once disparaged as completely
[48:22] worthless has turned into the powerful
[48:25] treatment that doctors are administering
[48:26] in the hospital to treat the uncurable
[48:29] infection, and now is the future of
[48:32] science. Mm.
[48:34] It's going to be so interesting.
[48:35] Could like, you know,
[48:37] change the class system in the country.
[48:39] Like, you know, like upper class could
[48:40] just be people with the best poop, and
[48:41] then lower class is if you've got like a
[48:43] really narrow gut microbiome, and your
[48:45] poop is useless, you can't sell it to
[48:46] anybody. Well, it's kind of fascinating
[48:48] that you say that because the issue is
[48:49] that if you look at the microbiomes of
[48:51] countries that are less developed than
[48:53] the US and the UK,
[48:55] um you know, they they they have less
[48:57] money,
[48:58] which the result of this is that they
[49:00] eat a more basic diet,
[49:02] which often is based upon whole grains
[49:04] and legumes.
[49:06] Right? Like, that's the essential, like
[49:07] beans and rice
[49:08] is like the essential diet. Yet, these
[49:10] things are actually so good for our gut
[49:13] microbes. Like, to me, legumes are the
[49:16] least talked about food that we should
[49:18] be talking about because they're high in
[49:20] fiber, they're high in resistant
[49:21] starches and polyphenols, all of which
[49:24] are prebiotics. And this is why when
[49:26] people eat more beans, they live longer
[49:27] with less disease. So, it's kind of
[49:29] interesting cuz like proper food, cheap
[49:30] food,
[49:31] is the food actually that is the best
[49:33] for us because it feeds these microbes.
[49:35] Lazy Westerners are going to get on a
[49:36] boat like they did once upon a time, the
[49:38] colonials, to go get the incredible, you
[49:41] know, they the the gold and the diamonds
[49:43] and whatever else they
[49:44] it's claimed that they stole from
[49:45] Africa, and they're going to get back on
[49:46] that boat and go over there and start
[49:48] stealing poop. I think that that I could
[49:49] definitely see that happening. There has
[49:51] actually been fights over when they they
[49:53] discover
[49:54] um
[49:56] uh prehistoric poop, like fossilized
[49:58] poop. There's fights over who gets to
[50:00] control that, because if you think about
[50:01] it, it's like Jurassic Park, right? In
[50:03] the beginning of Jurassic Park, there's
[50:04] that amber with the mosquito, and the
[50:06] needle goes in, you extract the DNA.
[50:08] What if we could extract the DNA from
[50:10] prehistoric poop
[50:11] and study that and potentially use that?
[50:14] Mhm.
[50:16] The poop studies that have been done,
[50:18] really compelled by them, cuz I hear
[50:19] that there's been a lot of sort of poop
[50:20] transplant studies done in in mice as
[50:22] well.
[50:22] Yeah. And what what what are we seeing
[50:24] from those studies? Well, okay, so we've
[50:26] talked about these different um
[50:28] conditions that are connected back to
[50:31] our gut microbes. Mhm. And part of the
[50:34] way that we prove this, of course, we
[50:36] want human research,
[50:38] but part of building
[50:40] uh our argument and and filling in the
[50:42] pieces of the puzzle is like mouse
[50:44] research.
[50:46] And these mice, it's we have complete
[50:48] control, and they're much more simple to
[50:50] manipulate. And so we have the ability
[50:52] to do a fecal transplant, even
[50:54] potentially from a human,
[50:56] to a mouse, and then see what happens.
[50:59] And so let me take you through a couple
[51:01] of examples of what we have seen in
[51:04] clinical studies, and I'm more than more
[51:05] than happy to point people towards the
[51:06] studies that I'm referring to.
[51:08] Um classic study. They took identical
[51:10] human twins. So again, we were talking
[51:12] about this in the beginning of the of
[51:13] the episode.
[51:14] Identical human twins, same genetic
[51:17] code,
[51:19] and in this case, one was obese and one
[51:22] is thin.
[51:23] And they have a different microbiome.
[51:26] And when you transfer human poop
[51:29] into mice,
[51:31] you also transfer the body type,
[51:34] even when you feed the mice the exact
[51:38] same food, the exact same number of
[51:43] calories.
[51:44] So we hear about this calories in,
[51:45] calories out concept, which by the way,
[51:47] we could talk about if you want to, but
[51:50] it's not perfectly true, and this is
[51:53] showing you the complexity that exists.
[51:55] Your microbiome impacts how you work
[51:58] with those calories. The mouse that uh
[52:02] receives the obese microbiome, it's like
[52:04] swimming against the current. The
[52:06] microbiome is making it basically so
[52:07] that that mouse absorbs all of those
[52:09] calories.
[52:10] And then the thin mouse mouse, um it's
[52:13] like swimming with the current at your
[52:14] back. It's a lot easier. You consume the
[52:16] same number of calories, you don't gain
[52:17] any weight.
[52:19] That's just metabolism. By the way, we
[52:21] have studies also diabetes can be
[52:23] transferred. We have studies in humans
[52:26] where you can actually do a fecal
[52:27] transplant from a person who does not
[52:29] have diabetes
[52:31] to a person who does have diabetes,
[52:33] and their blood sugar measures will
[52:34] improve
[52:37] in humans.
[52:38] We have uh immune studies. You can take
[52:41] a person who has ulcerative colitis,
[52:43] which we're talking about a moment ago,
[52:45] and transfer their poop into a mouse,
[52:46] and that mouse will have ulcerative
[52:48] colitis.
[52:50] We have um
[52:52] mood studies
[52:54] uh where you could take a human
[52:57] who has anxiety
[52:59] or depression
[53:00] um or PTSD
[53:03] and
[53:05] transfer their poop into a mouse,
[53:09] and the mouse receives the mood
[53:11] phenotype.
[53:13] So basically like again, this uh needs
[53:18] to be studied more in humans. We are
[53:19] more complicated. You can't just cure
[53:22] diseases like this by transferring poop
[53:24] among humans, yet.
[53:27] But when it comes to mice, where they
[53:29] are less complicated, it's very clear
[53:31] that the microbiome plays a central role
[53:34] in these conditions, because you can
[53:35] transfer the condition using human poop.
[53:39] And take me on a journey of what that
[53:40] poop's doing. So I I get the skinny poop
[53:42] from a skinny twin,
[53:44] and I put it into a mouse, the mouse
[53:45] gets skinny. Or I get the obese twin, I
[53:48] take the obese twin's poop, and I put it
[53:50] into a mouse, the mouse gets obese.
[53:53] What's going on in that mice's body to
[53:56] make it obese? I'm I'm assuming it's
[53:58] basically picking up some of the
[54:00] microbes, which are impacting the gut
[54:02] microbiome, which is creating a
[54:03] postbiotic compound, Yep. which is im-
[54:06] influencing its metabolism,
[54:09] or something something like that. You
[54:10] could eat the So if you have a
[54:12] microbiome designed to produce
[54:13] short-chain fatty acids, you and I could
[54:16] eat the exact same meal, but the person
[54:17] who has the microbiome designed to
[54:19] create short-chain fatty acids will get
[54:20] more short-chain fatty acids.
[54:23] And the and the product of this is that
[54:25] those short-chain fatty acids now will
[54:27] have effects throughout the entire body,
[54:30] including affecting our metabolism,
[54:32] affecting our blood sugar, affecting our
[54:34] insulin sensitivity, affecting our blood
[54:36] lipids after a meal, affecting fat
[54:38] storage, whether or not you turn on fat
[54:41] storage or whether you turn off fat
[54:42] storage and turn on fat burning.
[54:45] It really does shine a light on this
[54:46] calories in, calories out thing,
[54:48] because yeah, I mean, there's so many
[54:50] people who've talked about this a few
[54:51] times that just think
[54:52] you just have to eat below the required
[54:54] amount of calories for your body and
[54:56] you'll lose weight. But in that example,
[54:57] it proves that there's this other
[54:59] process going on that's going to
[55:00] determine
[55:01] I guess is it how many of those calories
[55:02] go through, or is it just how your body
[55:05] processes that energy?
[55:07] Part of it is part of it is
[55:08] thermogenesis, meaning fat burning.
[55:10] Yeah.
[55:11] Part of it is also what you poop out.
[55:14] Okay. They've actually found that people
[55:16] who have a healthier microbiome, they
[55:18] poop out more calories. Uh okay.
[55:21] Interesting.
[55:23] What do you think of the calories in,
[55:24] calories out thing? If someone comes to
[55:26] you and they say
[55:27] uh I want to lose weight, doc.
[55:30] And they say I've I've heard this
[55:31] calories in, calories out thing is the
[55:32] answer, so I'm just eating less. I mean,
[55:34] I eat lots of pizza, but I'm just having
[55:35] less calories.
[55:36] I don't I don't like that, obviously. So
[55:38] to me, dietary quality is the key. Um
[55:41] there's too many examples where dietary
[55:43] quality So first of all, our weight is
[55:45] our our health is not entirely
[55:47] determined by our weight.
[55:50] Is it a major factor? Yes, it is. But
[55:53] there's so much more. So dietary
[55:55] quality, study after study after study,
[55:57] shows us that dietary quality is crucial
[55:59] to the health of our microbiome,
[56:01] and also to our global health, our
[56:03] longevity, and our risk for disease.
[56:06] So to pretend that that doesn't matter
[56:08] would be completely false and
[56:09] inaccurate.
[56:11] Um the idea that calories is the only
[56:13] thing that matters, what I do want to
[56:15] say is this.
[56:17] There is some truth
[56:19] to the concept that calories matter.
[56:21] There's absolutely some truth to this.
[56:23] If you reduce your caloric intake, you
[56:25] will lose weight. The problem is that
[56:28] your body will compensate by slowing
[56:30] down your metabolism, and so then it
[56:32] puts you in a in a predicament where you
[56:34] can't continue to do this. It's not
[56:36] sustainable, because that weight loss
[56:38] eventually will stop,
[56:40] and then you will
[56:42] uh your appetite signals will grow so
[56:43] much that you will start to overeat. And
[56:46] then when you overeat, not only do you
[56:47] gain the weight back, you rebound.
[56:50] Yo-yo. You yo-yo, and you go above where
[56:52] you were before. Wow. And the problem
[56:53] with this is that when people lose
[56:55] weight, they don't just burn fat.
[56:57] They lose muscle mass. Like all weight
[57:00] loss is associated with a loss of muscle
[57:02] mass.
[57:04] When you gain the weight back, the
[57:05] muscle doesn't come back. You're just
[57:07] getting fat.
[57:09] So So the issue is you end up less
[57:11] healthy than when you started.
[57:13] To me, what I want is I want people to
[57:16] eat a diet where they can eat as much as
[57:18] they want without restriction until they
[57:21] are full,
[57:23] and still achieve their weight goals.
[57:25] And this is completely possible
[57:28] by consuming a diet that's high in
[57:29] prebiotics,
[57:30] because we hear so much about uh Ozempic
[57:34] or Wegovy,
[57:35] um which is semaglutide semaglutide.
[57:38] We hear so much about this, and it's a
[57:40] GLP-1 agonist. GLP-1 is a gut hormone
[57:45] that exists within our body,
[57:48] and uh it makes us feel full.
[57:52] We can stimulate
[57:54] GLP-1 through our dietary choices.
[57:58] If you eat the right food, which is
[58:00] basically a high prebiotic diet,
[58:03] you will activate the GLP-1, and you
[58:05] will naturally feel full.
[58:07] And the result of this is that in the
[58:09] process of actually activating your
[58:11] normal satiety signals, you will consume
[58:13] less calories. Satiety signals are
[58:16] basically hunger signals. Hunger
[58:17] signals. So basically like
[58:19] Yeah, so the issue that we all have is
[58:21] that we eat an ultra-processed diet.
[58:23] An ultra ultra-processed diet
[58:26] number one, makes us ravenous, right?
[58:28] Like we can't stop, we want it so bad.
[58:31] Number two, it doesn't activate those
[58:33] fullness signals.
[58:35] And so the result is when we eat an
[58:36] ultra-processed diet, we overeat.
[58:39] And then you feel like trash. You feel
[58:40] like trash for a couple of hours, and
[58:42] that is is the result of you overeating.
[58:44] You've thrown yourself metabolically out
[58:46] of balance.
[58:47] Right?
[58:48] Don't we all love the meal
[58:50] that tastes great, but you eat until
[58:53] you're full, and you stop, and actually
[58:55] feel energized,
[58:56] and don't need to take a nap or drink an
[58:58] energy drink to compensate for what you
[59:00] just did?
[59:01] And that happens when we do this the the
[59:03] old-fashioned way. By old-fashioned, I
[59:05] mean like prior to modern history, when
[59:07] ultra-processed foods came into uh
[59:10] existence. If we go back to the old way
[59:12] of eating, you would simply eat until
[59:15] you activate these hormones, things like
[59:17] GLP-1, which, you know, is concentrated
[59:19] in this drug, or peptide YY.
[59:22] These are gut hormones that basically
[59:24] tell our body when to stop eating.
[59:25] Everyone's going crazy about Ozempic. I
[59:27] keep hearing about this drug. I think
[59:29] Elon Musk recently said he had had it,
[59:30] and I know a few other people that have
[59:33] um started taking his impact there.
[59:35] I would say
[59:37] you know, then none of them are
[59:38] overweight necessarily. Yeah. Um but
[59:40] they're doing it because it's now been
[59:42] framed as kind of super drug
[59:43] which can help you drop weight super
[59:45] quickly by making you feel satiated.
[59:48] Yeah.
[59:49] What do you think of his impact?
[59:51] Well, let me come back to this. So,
[59:52] first of all, let me say that for people
[59:53] who need it, it's I'm glad it's there.
[59:56] Um I don't think that the entire world
[59:58] needs Ozempic in order to be healthy. Is
[60:00] there any side effects or 100%.
[60:03] 100%. First of all, digestive symptoms.
[60:06] Um massive
[60:08] uh massively common digestive symptoms.
[60:10] But there's also long-term risks and
[60:12] many of which we don't simply know much
[60:13] about because people haven't been using
[60:15] the drug long enough for us to really
[60:17] fully understand what happens if you use
[60:19] because once you start using it, you're
[60:21] not going to stop.
[60:22] If you stop, you gain all the weight
[60:23] back.
[60:25] So, once you start using it, you're
[60:26] basically committing to however old you
[60:28] are, you're going to be doing this for
[60:29] years and years if you know, decades.
[60:32] Um we don't know what happens after a
[60:33] couple of years. Isn't it kind of
[60:35] skipping a step in the process of
[60:37] developing the gut microbiome taking
[60:39] Ozempic?
[60:40] Yeah, I think that's the point is that
[60:42] if we so, you know, if we look at our
[60:44] countries, the US and the UK,
[60:46] um there's a major fiber deficiency.
[60:49] And I don't think, you know, I realize
[60:51] I'm out there pounding the drum on this,
[60:52] but I don't think this is talked about
[60:53] enough. Perhaps because people don't
[60:56] think that fiber is sexy.
[60:58] But I think fiber is sexy because it's
[61:00] so crucial and important to our to our
[61:02] health and this is an example where this
[61:04] is 100% true. So,
[61:06] uh 95% of Americans are deficient in
[61:08] fiber. The average woman is getting 15 g
[61:11] of fiber per day.
[61:12] She's supposed to be getting at least 25
[61:14] in the US.
[61:15] The average man is getting 18 g of fiber
[61:17] per day. He's supposed to be getting 38.
[61:20] That's a massive massive deficiency.
[61:23] And the issue is that the fiber is what
[61:26] actually empowers the gut microbes. By
[61:28] the way, through short-chain fatty
[61:29] acids.
[61:30] The fiber is what empowers the gut
[61:32] microbes through short-chain fatty acids
[61:34] to release these gut hormones so like
[61:35] GLP-1 and peptide YY. So, my thing is
[61:38] this.
[61:39] Cuz again, like our health is not
[61:41] determined exclusively by our weight
[61:43] balance. There are other things other
[61:45] than that.
[61:46] Why don't we cons try consuming these
[61:48] foods?
[61:49] The average American is 10% of their
[61:51] calories from plants, fiber-containing
[61:53] food.
[61:54] What if we can make that 30% or 50%?
[61:58] I think that we would see a massive
[61:59] difference. There was a study that was
[62:01] done. It's one of my favorite studies of
[62:02] all time by uh
[62:05] uh
[62:05] professor in New Zealand. His name is
[62:08] Andrew Reynolds.
[62:10] And he compiled all of the available
[62:11] data on fiber. What happens when people
[62:13] consume more fiber?
[62:15] Here's what happens.
[62:18] They lose weight.
[62:19] Uh they are less likely to have a heart
[62:21] attack.
[62:23] They're less likely to die of heart
[62:24] disease.
[62:25] They're less likely to have a stroke.
[62:27] They're less likely to be diagnosed with
[62:28] diabetes.
[62:30] They're less likely to be diagnosed with
[62:31] multiple different types of cancer.
[62:34] They're less likely to die of cancer.
[62:36] Um their blood pressure goes down.
[62:38] Their blood sugar control improves.
[62:40] Their cholesterol goes down.
[62:42] Okay.
[62:43] Like that's
[62:44] sitting there for us.
[62:46] Available. All we have to do is make the
[62:48] dietary changes. And again, what happens
[62:51] in that process is you consume more
[62:53] fiber. It comes into contact with your
[62:55] gut microbes. They release short-chain
[62:56] fatty acids and they have healing
[62:57] effects throughout your entire body.
[62:59] So, to me, I agree with you. I think
[63:01] that we're missing this
[63:03] um this middle piece and when we're
[63:04] reaching for something that's an
[63:06] expensive drug, it's very expensive.
[63:08] We're reaching for something that's an
[63:09] expensive drug and it has a very real
[63:12] risk of side effects and it also has
[63:14] risk in the sense that we just don't
[63:15] know what happens after you take it for
[63:17] a couple of years.
[63:18] Um I I don't understand why we would do
[63:21] that when think of the benefits that I
[63:22] just listed by simply increasing your
[63:24] fiber intake.
[63:25] I have so many conversations with my
[63:26] friends about
[63:28] various drugs that they're taking,
[63:30] performance drugs, modafinil, Ozempic,
[63:33] etc.
[63:34] And when I speak to them, they they're
[63:36] very passionate that there's no side
[63:37] effects on all all of these sort of
[63:40] things that I consider
[63:42] cheating. Yeah. And I and I have to
[63:44] caveat this because there are some
[63:46] people who are in a situation with
[63:48] diabetes or other cardiovascular issues
[63:52] um
[63:54] who can have their lives saved with some
[63:57] of these drugs. Yeah.
[63:59] But for the most part, the people that I
[64:01] know that are consuming these drugs
[64:02] aren't doing it for that reason. They're
[64:03] doing it for vanity reasons or for
[64:04] performance reasons where it's like
[64:06] taking a shortcut and every shortcut I
[64:08] believe in life comes with a cost. Yeah.
[64:10] You're talking like a doctor. You're
[64:12] talking like a doctor because basically
[64:13] what you're talking about is risk versus
[64:16] risk versus benefit. And the way that I
[64:19] think and every other doctor thinks
[64:20] about their patient is does the benefit
[64:22] outweigh the risk? But there is always
[64:24] risk in association with these drugs.
[64:27] And what makes me different from most
[64:29] other doctors
[64:31] where I turned the corner in my career
[64:32] is when I started the ask ask the
[64:34] question, why are we waiting until we
[64:35] get to the point that we need to write a
[64:37] prescription for a drug? Why are we
[64:38] waiting until that point?
[64:40] Why are we not intervening in a much
[64:42] earlier point where we could transform a
[64:44] person's life and get them to a place
[64:47] where they never actually get this
[64:48] disease or if they get this disease,
[64:50] it's so much easier for us to control
[64:52] that. And this is so to me, what I come
[64:54] back to is basically what you're getting
[64:55] at is why would we why would we take a
[64:58] drug
[64:59] if we could change our diet and our
[65:01] lifestyle
[65:03] and actually protect ourselves? It's
[65:04] easier.
[65:05] It is much easier. Yeah, it is it is
[65:07] much easier. There's no doubt, but the
[65:08] problem is you pay a price for that.
[65:11] And the price is unobvious. So, you've
[65:12] got an easier option where the benefits
[65:15] are clear and the cost, the risk is
[65:18] unobvious.
[65:19] A
[65:20] logical human being would take that path
[65:22] if they can afford it.
[65:23] I agree.
[65:24] The issue is that these are not the same
[65:28] things though. And what I mean by that
[65:31] is that um you have diabetes.
[65:34] Okay? Like like hypothetically. I hope I
[65:36] don't. Jeez. Yeah, yeah. I hope you
[65:38] don't. Yeah, yeah.
[65:40] Uh hypothetically, you have diabetes.
[65:41] Okay, cool. We give you a drug for your
[65:44] diabetes.
[65:46] Um that drug covers up the issue.
[65:48] I can get your blood sugar down. But
[65:51] that's not fixing the problem.
[65:53] I'm not actually fixing your diabetes,
[65:55] right? So,
[65:57] to me, like we shouldn't equate um
[66:01] taking a drug and
[66:04] like controlling a disease on some
[66:06] level, but truly what we're doing is
[66:08] we're just putting a sheet over the
[66:09] problem so you don't see it anymore.
[66:12] Right? Does it does it result in better
[66:13] outcomes long-term? Are you healthier as
[66:15] the result of controlling your diabetes
[66:17] with a drug? 100% yes.
[66:19] No doubt.
[66:21] But what if we could reverse your
[66:22] diabetes? Diabetes, type 2 diabetes,
[66:25] which is the uh
[66:26] a kind that people acquire as an adult
[66:30] is highly reversible. Most people don't
[66:32] realize that. Like you don't need to be
[66:34] drug-dependent on di- on diabetes drugs
[66:37] in order to fix this issue. Take them
[66:39] when you need them.
[66:40] But let's work on the root cause and by
[66:42] working on the root cause, we can
[66:43] actually reverse the true problem and
[66:45] get you back to a place where you don't
[66:46] need the drug at all. But doesn't that
[66:47] require discipline and willpower and
[66:48] motivation?
[66:50] Well, I think I think it requires
[66:52] understanding the path forward and
[66:54] making choices that are sustainable and
[66:56] that make you excited. Like I don't I'm
[66:58] I would never ask a person to make
[66:59] choices that make them miserable. I'm
[67:01] asking people to make choices that make
[67:03] them feel great, make them feel
[67:04] energized and yet at the same time
[67:07] actually are contributing to better
[67:09] health so that they can live longer with
[67:11] less disease and be in a position that I
[67:13] want to be in, which is that I want to
[67:15] be in my 80s and still like cutting a
[67:16] rug and dancing. Like dance with my
[67:18] grandkids. So, let's close off on this
[67:19] subject of poop.
[67:21] Um my team actually prepared some poop
[67:24] samples earlier on because I was
[67:26] wondering as a gastroenterologist
[67:28] Yep. I wondered that if you could look
[67:30] at someone's poop and determine whether
[67:32] they have good gut health.
[67:33] Yeah. And if you can understand what's
[67:34] going on in their body just by how their
[67:36] poop looks because poop comes in many
[67:38] shapes and sizes.
[67:39] So, what I have here
[67:41] is
[67:42] a variety of different shapes and sizes
[67:45] of poop. Yeah. For anyone that can't
[67:47] see, well, look at the screen if you're
[67:49] listening to the podcast on Spotify or
[67:51] YouTube. Um
[67:53] different shapes and sizes of poop here.
[67:55] This is real human poop.
[67:58] So, I'm going to pass you that so you
[67:59] can play around with it. Yeah.
[68:03] And what why does the shape and size of
[68:04] our poop tell us anything? Why does it
[68:06] matter? And how is it indicating
[68:08] something that's pertinent to our
[68:09] overall health? Well, because it goes
[68:10] back to what you mentioned earlier,
[68:12] which is that 60% of our
[68:14] 60% of the weight of our stool is
[68:16] actually microbial in origin. So, if you
[68:18] want a window into your microbiome, look
[68:20] at your poop. You don't necessarily need
[68:22] to go and do an expensive test. Like
[68:24] quite simply looking at your poop is one
[68:25] of the ways that you can tell what's
[68:26] going on.
[68:28] So, there was a study that was done in
[68:29] the 90s.
[68:31] It's a long time ago. And it was less
[68:33] than 2,000 people
[68:35] exclusively in the city of Bristol.
[68:38] And it led to the creation of a chart
[68:40] called the Bristol stool scale.
[68:42] Right here. I'll put it on the screen.
[68:43] Yeah.
[68:45] And we're going to we're going to run
[68:46] through this, but before we do, I want
[68:48] to mention a few things real quick. As
[68:49] the US medical director of Zoe, I'm
[68:51] proud of my contribution as a
[68:53] gastroenterologist, as a physician to
[68:56] the work that we're doing there. And we
[68:58] not only did the blue poop study, which
[69:00] we've talked about already, which is
[69:01] that you can eat your muffins and figure
[69:03] out your gut transit time.
[69:05] But we also did a couple of other
[69:06] things. One is called the blue poop
[69:07] challenge.
[69:09] Um where we had over 20,000 people
[69:11] across the planet who were basically
[69:13] eating blue muffins and then reporting
[69:15] back to us on what was going on with
[69:16] them.
[69:17] And then more recently, so again, the
[69:19] Bristol study was 2,000 people
[69:22] exclusively in the city of Bristol.
[69:24] We recently did the largest study across
[69:28] the entire UK on poop
[69:31] and what people were doing in terms of
[69:33] their bowel movements.
[69:34] So, it was called the big poo review and
[69:36] we had 142,000 people from across the UK
[69:39] basically fill out a 17-question survey.
[69:42] And part of what we were looking at was
[69:43] their Bristol stool form. We were also
[69:45] looking at how often they poop. By the
[69:47] way, the average person poops 1.7 times
[69:49] per day.
[69:50] Um and we're also looking at like how it
[69:52] associates with different conditions.
[69:55] So, as an example, one in five people in
[69:57] the UK are constipated.
[69:59] One in six people in the UK have
[70:01] diarrhea.
[70:02] So, it's interesting to take a look at
[70:04] all these things. So, now getting into
[70:05] the Bristol stool chart
[70:08] the uh
[70:10] the dream That is real poop. This is the
[70:14] It's lovely.
[70:15] Um
[70:16] this is the dream.
[70:18] This is where we all want to be and this
[70:20] is a Bristol four. The Bristol four is
[70:22] the classic uh where I come walking out
[70:25] of the bathroom in slow motion and rock
[70:27] music is jamming and doves are flying in
[70:30] slow motion and I just I'm such a stud.
[70:33] So, and that's after a Bristol four. My
[70:34] wife knows what happens when I come out
[70:36] looking like that. It's soft and formed,
[70:39] okay, and it's like a sausage or a
[70:41] torpedo.
[70:42] Um so, pretty smooth. Now, um when we
[70:45] move from a four to a three, a three is
[70:49] not that big of a deal
[70:51] but it is getting some cracks and
[70:52] crevices in it.
[70:54] All right. So, and we're moving towards
[70:55] constipation. Now, a three, you know, uh
[70:59] a little more fiber, a little more
[71:00] hydration, some exercise.
[71:02] These are simple things that can help to
[71:04] get you back to a four if you're having
[71:06] one of these, a three. But that moves us
[71:08] to a Bristol two where we are truly
[71:10] getting into constipation territory
[71:11] here.
[71:12] And basically with this is like if you
[71:14] took a whole bunch of marbles of poop
[71:16] and jammed them together so it still
[71:18] forms into something but it looks like a
[71:20] pack of marbles of poop that are stuck
[71:22] together.
[71:23] So, that's a Bristol two stool. That's
[71:25] constipation. And then finally, a
[71:28] Bristol one is when you're having the
[71:30] rabbit the rabbit pellets and they're
[71:31] hard.
[71:33] They're not easy to get out and
[71:34] sometimes they're a lot bigger than
[71:35] this. This is These are small.
[71:37] Um
[71:38] so, you would you would form this up
[71:40] into what would be like a golf ball.
[71:43] And that golf ball
[71:45] would be uh like a Bristol one. Okay.
[71:48] All right.
[71:49] You form it up into a hard ball like
[71:52] this. Um but perhaps even bigger.
[71:55] And it's actually hard for a person to
[71:56] pass this. It's so big, it's so hard
[71:59] um that your bottom has a
[72:01] uh a problem relaxing to let it out.
[72:04] Okay, so Bristol one and two are forms
[72:06] of constipation.
[72:08] Let's go back to the middle. And we're
[72:09] going to start from five. The The stool
[72:11] is soft. It's not hard. It's not lumpy
[72:14] bumpy. It's soft but it's starting to
[72:16] break into blobs, different pieces of
[72:19] poop.
[72:20] Um
[72:21] so and we're moving towards
[72:24] uh
[72:24] we're moving towards diarrhea where like
[72:27] just like fragments of solid stool
[72:30] are a Bristol six. And then when it's
[72:32] just like or
[72:34] the other thing a Bristol six could be
[72:35] like a cow pie.
[72:37] Um where there's no form.
[72:39] It's just
[72:40] someone plopped down this formless
[72:43] patty.
[72:44] And a Bristol seven finally is straight
[72:47] liquid.
[72:49] Straight liquid. And how is this
[72:51] pertinent to our gut microbiome, our
[72:53] health? What does this tell us about our
[72:55] health? There's been now multiple
[72:56] studies including our work at Zoe on the
[72:58] blue poop study uh that was published in
[73:00] the journal gut. There's now been
[73:02] multiple studies where basically what
[73:03] they found is that if you can look at
[73:05] which of these Bristol types you have,
[73:07] it does give us some insights into your
[73:10] gut microbiome and what's happening
[73:11] there.
[73:12] So, now where do we want to be? In a
[73:14] perfect world, we want to be somewhere
[73:16] on the spectrum of three, four, or five.
[73:19] We ideally want to be a four. You're not
[73:22] uh unhealthy if you have a three or a
[73:25] five. So, if this type four poop, which
[73:27] is kind of like a sausage, it's kind of
[73:28] like a smooth sausage Yeah. is optimal
[73:33] how does one do that? What is turning it
[73:35] into a type four? What are What are they
[73:36] eating, doing? Yeah. Interesting
[73:38] question. We
[73:40] uh
[73:41] one of the things that we found in the
[73:43] big poo review, which is our nationwide
[73:45] survey of 142,000 people. We actually
[73:47] looked at what they were eating.
[73:49] And we were able to find associations
[73:52] between fiber intake and specifically
[73:54] plant-based food intake and having a
[73:56] number four. So, in other words, we
[73:58] found associations between fiber intake
[74:01] and basically plant-based food intake
[74:03] and having a number four. So, basically
[74:05] what that means is the people that were
[74:06] having a number four bowel movement were
[74:08] consuming more uh legumes, whole grains,
[74:11] fruits, and vegetables.
[74:13] The people who were having whether it be
[74:14] a type one or a type seven, they
[74:16] actually were quite similar in terms of
[74:18] their diet, which is that um they
[74:21] actually were consuming lower amounts of
[74:23] fiber.
[74:24] Now, the other thing to look at too is
[74:27] um actually some studies have found that
[74:30] people who have more on the spectrum of
[74:32] constipation tend to have a higher fat
[74:35] diet
[74:36] tend to typically consume more animal
[74:38] products, which of course are higher in
[74:39] fat.
[74:40] And people that are more on the uh loose
[74:43] or diarrhea side of things
[74:46] tend to be consuming more plant-based
[74:48] foods.
[74:49] So, now you could have a very healthy
[74:51] diet and be having a Bristol five.
[74:54] And that actually is not problematic.
[74:56] And the reason that you're having the
[74:57] Bristol five is because you're consuming
[75:00] so much fiber that actually producing a
[75:02] lot of short-chain fatty acids and those
[75:03] short-chain fatty acids, they're like
[75:05] lubricants for your poop.
[75:08] And the gut transition time, how does
[75:10] that relate to these different types of
[75:12] poop? As you were saying that, I was
[75:13] thinking the one in seven, the type one
[75:15] and the type seven, the type one being
[75:17] the sort of hard nuts and the type seven
[75:19] being basically diarrhea. I was assuming
[75:21] that those are the poop types that would
[75:24] happen
[75:26] So
[75:26] with a lower and a super high gut
[75:27] transition time. That's right. So, a
[75:29] slow gut transit time, which is a gut
[75:31] transit time more than 58 hours. So,
[75:33] again we're and this is all with the
[75:34] blue muffins. You eat the blue muffin,
[75:37] it comes out 58 hours later
[75:39] you are more likely to be having a
[75:40] Bristol one or Bristol two, which is the
[75:43] classic constipation form. There's no
[75:46] way
[75:47] no way that you would have slow gut
[75:49] transit time and have a Bristol seven.
[75:51] That's not possible. The diarrhea. Yeah,
[75:53] the diarrhea. So, diarrhea comes out
[75:55] fast and these sort of hard nuts, they
[75:56] take typically a long time.
[75:58] That's right. And the reason why this is
[76:00] happening
[76:01] you know, um so when water moves through
[76:03] the intestines cuz a ton of water moves
[76:05] through the intestines. And one of the
[76:07] jobs
[76:08] that our colon has, the large intestine
[76:10] is to pull the water out.
[76:14] So, the more time that something spends
[76:16] inside the colon
[76:18] the more it's actually going to do that,
[76:19] pull the water out. This is the reason
[76:21] why when we have fast transit, it's high
[76:23] in water.
[76:25] And this is also the reason why when
[76:26] it's slow transit, it's extremely dry.
[76:29] Okay, so that's the shape and size of
[76:31] the poop. But what about colors of poop?
[76:32] I've got some different colors of poop
[76:34] here. I've got some red, some blue, some
[76:36] black, some green, some whites, and some
[76:38] yellows.
[76:38] Yes. How is color pertinent to health
[76:42] and everything we've been discussing?
[76:43] All right, let's break this down. So,
[76:44] first of all, why is our poop brown? The
[76:46] answer to that question has to do with
[76:48] bile.
[76:50] Bile is produced by our liver.
[76:52] It's actually involved heavily in
[76:54] digestion of fat.
[76:56] So, um when we for example eat a fatty
[76:59] meal, our gallbladder will squeeze.
[77:01] People that have gallbladder issues know
[77:02] what I'm talking about. You eat a fatty
[77:04] meal, your gallbladder squeezes. Bile
[77:06] then mixes in your intestines with the
[77:08] food and the bile helps to absorb the
[77:11] fat.
[77:12] Um that bile is what makes our poop
[77:14] brown.
[77:15] Now, that becomes particularly relevant
[77:17] if we're talking about a white poop.
[77:20] People poop white? Some people poop
[77:22] white. No way. Yes.
[77:24] And the reason why uh a person would
[77:27] have a white poop is if there's a
[77:28] blockage
[77:30] that stops the bile from mixing with
[77:32] their intestines.
[77:34] Um
[77:35] on the flip side,
[77:36] uh if you are struggling to process your
[77:38] fat
[77:39] you could have a yellow poop.
[77:41] So, and this could be a person who has
[77:43] like a pancreas issue for example,
[77:44] chronic pancreatitis. And so, if they're
[77:47] not able to digest their fat
[77:50] they have a fatty poop.
[77:52] It may come out yellow.
[77:53] And one of the things that they'll
[77:54] notice is that there may be an oil slick
[77:57] at the top of the toilet bowl. Right.
[77:59] That's fat. Oil is fat.
[78:01] So, all right, you've never had a Have
[78:03] you ever had a green bowel movement?
[78:04] None of your business.
[78:07] Answer the damn question.
[78:09] No, I haven't. No. Okay.
[78:11] Um I have. Oh, really? Yeah. There's a
[78:13] couple of reasons. Some are healthy,
[78:14] some are not. Right. So, you could have
[78:17] a um you could have diarrhea like from
[78:19] an infectious cause.
[78:21] Um an example could be something called
[78:22] giardia, which is a parasite.
[78:24] Mhm.
[78:25] And that'll give you green poop. But you
[78:26] could also go too hard on the smoothies.
[78:29] I was drinking my 40 oz of green
[78:30] smoothies a day and my poop would come
[78:32] out green. It's interesting. We're going
[78:34] to We're about to get into some that are
[78:35] really important. Um before I do that,
[78:37] let me just mention real quick the blue.
[78:39] So, the blue poo
[78:41] um you could get a blue poo from eating
[78:43] blueberries.
[78:44] Um particularly if you eat a lot of
[78:45] them.
[78:46] Uh or alternatively, of course this is
[78:49] the blue muffin, the blue poo challenge.
[78:50] Mhm. So, and perhaps what we could do in
[78:52] the show notes is give people the recipe
[78:54] for how they can go about doing that if
[78:56] they if they're interested.
[78:58] All right.
[78:59] Um red and black
[79:01] So, we have to talk about Let's Let's
[79:03] start with red.
[79:04] Because of course red we think about
[79:06] blood.
[79:07] And um and I have a rule
[79:10] which is that if you see blood in your
[79:11] stool, that's not normal.
[79:14] And to me, that's grounds to talk to a
[79:16] doctor.
[79:17] And you know, then there's different
[79:18] levels of intensity of how seriously we
[79:21] check it out.
[79:22] But Stephen,
[79:23] colon cancer,
[79:25] which can present with red stool.
[79:28] Um colon cancer is the number two cause
[79:30] of cancer death in our countries.
[79:34] In the United States, 150,000 people are
[79:36] diagnosed per year.
[79:39] It's highly preventable.
[79:41] And it's shifting towards younger
[79:42] people.
[79:44] There has been a change in the last few
[79:47] years in terms of colon cancer, where as
[79:50] an example,
[79:51] a person of
[79:53] your generation, you and I are pretty
[79:55] close, I think, but I'm a little bit
[79:56] older.
[79:57] A person of your generation
[79:58] is four times more likely
[80:01] to be diagnosed with rectal cancer
[80:03] during their lifetime than my parents
[80:04] were.
[80:06] And twice twice times more likely
[80:09] to be diagnosed with colon cancer
[80:11] compared to my parents' generation.
[80:13] So, there's been this shift, and it's
[80:16] also affecting younger people. So, my
[80:18] point is this.
[80:19] Um I've had patients who come to me,
[80:21] they go, "I saw a little bit of blood in
[80:22] my stool."
[80:23] Do a colonoscopy and discover that they
[80:26] have a massive polyp, which is a
[80:28] precursor to cancer.
[80:31] And by removing the polyp, we just
[80:33] basically stopped them from developing
[80:35] cancer.
[80:36] So, I take it seriously when you see a
[80:39] poop that is coated in red.
[80:42] All right? Now, that red may be just on
[80:44] parts of it, like it is here,
[80:46] where that's typically bright red coming
[80:49] from the bottom.
[80:50] So, that would be either something in
[80:52] your rectum,
[80:53] could be hemorrhoids,
[80:55] could be an anal fissure,
[80:57] could also be a polyp in the rectum.
[80:59] Okay. But I think what I come back to is
[81:01] I would encourage people to get checked
[81:03] out because just seeing the bright red
[81:05] blood doesn't mean it's hemorrhoids.
[81:06] Don't assume that.
[81:07] Right? Particularly with cancer shifting
[81:09] towards younger people, I think it's
[81:10] important to like get checked out. On
[81:12] that point about cancer shifting towards
[81:13] younger people, is that because our
[81:14] diets are changing?
[81:17] I think so. I think it's I think it's I
[81:19] think it's um the shift generationally
[81:21] that's taken place in terms of our
[81:22] diets.
[81:24] Um I also think that there's a
[81:25] microbiome element. The The connections
[81:27] between the gut microbiome and colon
[81:29] cancer are as powerful
[81:32] as any type of cancer.
[81:35] And at the same time,
[81:36] what protects us,
[81:38] and I think you know where I'm going to
[81:39] what I'm going to say,
[81:40] it's the fiber
[81:42] and the short-chain fatty acids.
[81:44] And in that study that I was mentioning
[81:45] earlier from Andrew Reynolds, the
[81:47] professor from New Zealand,
[81:49] um actually there there was a powerful
[81:51] association between fiber consumption
[81:53] and protecting ourselves from colorectal
[81:55] cancer. So powerful that for every gram
[81:58] 5 g of fiber that we increase in our
[82:00] diet, we are getting a significant
[82:02] reduction in our risk. So, it's not just
[82:04] do you eat fiber or not, it's actually
[82:06] how much fiber do you eat, and the more
[82:07] the better. So, you know what? I should
[82:09] mention real quick, red stool can also
[82:11] come from eating beets.
[82:13] It will almost always happen like
[82:15] literally, you know, 24 to 48 hours
[82:17] after you eat the beets. So, don't be
[82:19] surprised when that's the case, you may
[82:21] see a little bit of red stool.
[82:22] Um black stool can come from benign
[82:25] places. So, an example is bismuth. So,
[82:28] like Pepto-Bismol.
[82:30] So, you have a you have a stomach ache,
[82:32] and then you take some Pepto-Bismol, and
[82:35] um so, but the issue with this is it
[82:36] will actually give you black stool. So,
[82:38] if you're having a bad stomach for a
[82:39] couple days in a row, it could turn
[82:41] black. But the other thing that turns
[82:43] your stool black that people need to
[82:44] know about is a slow GI bleed.
[82:48] Bleeding into your stomach,
[82:50] specifically.
[82:51] Um because that bleeding is happening
[82:53] higher up in your intestines, and then
[82:55] it has to pass all the way through that
[82:57] like intestinal transit time, right?
[82:59] Because there's such a delay, by the
[83:00] time it gets down to your rectum, it's
[83:02] now black. It's not red anymore.
[83:04] So, black stool can be indicative of of
[83:06] bleeding. The way that we can
[83:08] differentiate this
[83:10] is when it's blood,
[83:11] it smells terrible. Oh, now we've got to
[83:14] start smelling our own poop.
[83:15] Yeah. Well, you don't have to stick your
[83:17] nose into it. It's so clear.
[83:20] Like it will be so clear. Okay.
[83:21] Okay. When I'm in the hospital, like I
[83:24] will be walking through, and I can
[83:25] literally tell when a consult is coming
[83:27] because I can smell this diagnosis.
[83:29] Really? Yeah. Um so, anyway, the the
[83:33] stool will turn black. It will smell
[83:35] terrible, and it will be like tar.
[83:37] That's what makes it different than if
[83:38] you were to, for example, take
[83:39] Pepto-Bismol.
[83:41] We released it the first time, and it
[83:43] sold out instantly. We released
[83:44] conversation cards again, and they sold
[83:47] out instantly for a second time. We've
[83:49] updated the cards, put all the new
[83:51] questions in, and we've introduced a
[83:53] twist. On the back of the conversation
[83:55] cards now, we've got different levels of
[83:58] vulnerability. So, level one, these are
[84:00] more sort of surface-level questions,
[84:02] and by the time you get down to level
[84:03] three, the questions become a little bit
[84:06] more challenging, a little bit more
[84:08] vulnerable, and that's really where
[84:10] connection happens. The brand new
[84:13] version two updated conversation cards
[84:15] are out right now at the
[84:17] conversationcards.com.
[84:20] Quick one. As you might know, a company
[84:21] that I've invested in is now also a
[84:23] sponsor of this podcast, and they're
[84:25] called Zoe. And I'm coming to you today
[84:27] with a warning. It is January, and it's
[84:30] all of those diet companies' favorite
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[85:14] to get £50 off your Zoe kit for a
[85:17] limited time only. Use it right now. I'm
[85:20] really interested in this idea that
[85:23] we can
[85:24] give our gut microbiome to our kids, but
[85:27] also in the twin studies, they have such
[85:29] a diverse gut microbiome. So, how much
[85:32] of our gut microbiome are we inheriting
[85:34] from our our parents, our grandparents,
[85:36] et cetera, if any at all?
[85:38] Well, we're certainly inheriting some.
[85:41] Um and particularly when we're kids, as
[85:42] a newborn, you're going to most closely
[85:44] resemble the gut microbiome of your
[85:46] mother. Mhm. And that that association
[85:48] and sharing is much more profound if you
[85:51] were born through a traditional vaginal
[85:53] delivery
[85:54] and if you're breastfed.
[85:57] So, that connection between mom and baby
[85:59] actually helps to facilitate the
[86:01] transfer of microbes to the baby that
[86:03] leads to health.
[86:05] And this is part of the reason why when
[86:06] you disrupt these things, which by the
[86:08] way, I should mention,
[86:09] sometimes these things are inevitable.
[86:12] So, I have three kids. They were all
[86:13] born by cesarean. It's not the way that
[86:15] we wanted it to be, but it's what
[86:16] happened. You can have healthy kids who
[86:18] are born by cesarean.
[86:19] Um so, but uh when we disrupt these
[86:22] things, whether it be cesarean section
[86:25] or uh or bottle-feeding instead of
[86:28] breastfeeding
[86:29] or antibiotics,
[86:31] we see downstream the same effects.
[86:34] Increased likelihood of obesity,
[86:37] increased likelihood of allergic
[86:39] conditions, including food allergies and
[86:42] um asthma,
[86:44] increased likelihood of autoimmune
[86:45] conditions, including celiac disease and
[86:47] type 1 diabetes.
[86:50] So, when you disrupt the the developing
[86:52] gut microbiome in that child,
[86:54] um you increase the risk of these things
[86:56] happening subsequently. And there's been
[86:58] some interesting studies
[86:59] where they will look at the microbiome,
[87:01] they'll look in the diaper
[87:03] of a child who's 6 months or a year old,
[87:05] and they can, based upon that, they can
[87:07] predict who within the next 4 to 5 years
[87:10] is going to develop an allergic or
[87:12] autoimmune condition. So, so getting
[87:14] back to uh the sharing of microbes, like
[87:16] yes, there is this connection between
[87:18] mom and child, but actually um this is
[87:20] an evolving thing throughout our life.
[87:22] And there's new research that I think is
[87:24] really important about human connection.
[87:28] And in this study, what they found is
[87:29] that people who shared spaces together
[87:32] through connection,
[87:33] uh they, number one, had a healthier gut
[87:35] microbiome
[87:36] than people who live by themselves.
[87:40] Number two, they share more microbes
[87:42] together. So, like for example,
[87:44] me with my wife,
[87:46] um we share more microbes together than
[87:48] I do with my siblings.
[87:50] Wow. And then the other thing that was
[87:51] kind of fascinating from the study
[87:54] is the um
[87:56] the strength of the relationship
[87:57] matters.
[87:59] So, uh I think we can all agree
[88:01] sometimes relationships aren't a good
[88:03] place,
[88:04] and sometimes they're in a bad place.
[88:05] Mhm. Right? And that's like a whole
[88:07] spectrum and different conversation. But
[88:10] actually where it is on that spectrum
[88:12] impacts your gut microbiome.
[88:15] They found that the couples that were
[88:16] sharing uh the most microbes were the
[88:19] ones that actually had the most um
[88:21] connection in terms of their
[88:22] relationship. Whereas the people who
[88:24] were disconnected from one another, they
[88:26] weren't sharing so many microbes. Now,
[88:28] you could say like is that because
[88:29] they're having less sex? Could it be
[88:32] that they just like physically aren't
[88:34] even close to one another? I suppose
[88:36] that's all possible, but these are also
[88:38] people where they like they they
[88:39] controlled for their diet. So, it's not
[88:40] a dietary thing. So, like I think that
[88:43] the, you know, the takeaway from my
[88:44] perspective
[88:46] is the power of human connection
[88:49] is more important in 2023, 2024.
[88:54] It's more empower more important in this
[88:56] moment than it's ever been.
[88:58] And many aspects of our life are pulling
[89:01] us away from this.
[89:03] Our devices,
[89:04] social media. I mean, I'm very active on
[89:06] social media, but
[89:08] let's be transparent about this.
[89:10] This is pulling us away from the ability
[89:12] to sit down with another person, and
[89:13] look them in the eye, talk to them, have
[89:16] a meaningful conversation, and feel
[89:17] connected to that person, and because
[89:18] you feel connected, you reap the
[89:20] rewards, which do include better gut
[89:22] health. But but that's super interesting
[89:23] because it yeah, it does make a case
[89:25] that the people we surround ourselves
[89:26] with we tend to think of psychology,
[89:27] right? We tend to think that if you
[89:29] surround yourself with a certain type of
[89:30] person, it's good for your psychology if
[89:32] they're positive or they're negative,
[89:33] etc. But there's actually a case that
[89:36] people the people we surround ourselves
[89:38] with have an impact on our physiology,
[89:39] our bodies, our biology, our gut
[89:41] microbiome, and that has an upstream
[89:43] effect on everything. That's true, but
[89:45] you also can't disentangle or separate
[89:47] out from the fact that the positive
[89:49] influence of a person also really
[89:51] matters. Yeah. Because where you're at
[89:53] from an emotional perspective, and I
[89:54] think this is an important thing for
[89:56] people to understand um that where
[89:58] you're at from an emotional perspective
[90:00] does manifest in your gut health.
[90:03] And this is the reason why, for example,
[90:06] if a person's going to go and do public
[90:07] speaking, and they're not comfortable
[90:09] with public speaking,
[90:10] they may just have a little bit of
[90:12] jitters, a little bit of nausea, or
[90:14] queasiness, but it can also
[90:17] uh snowball into something bigger and
[90:19] worse such as fold fold you over type
[90:22] cramps,
[90:23] right? So, and that's many people will
[90:26] manifest their stress in their gut.
[90:29] That's an acute example. By acute, I
[90:32] mean like this specific situation
[90:34] context that you're uh involved with.
[90:37] But what happens if your life is stress?
[90:40] And the answer to that question is
[90:42] actually very clear.
[90:43] Because people who, for example, have
[90:45] childhood trauma,
[90:47] they will subsequently go on and be far
[90:49] more likely to develop digestive issues,
[90:51] but other gut-related issues. And there
[90:54] was an interesting study, Steven, that
[90:55] was done among 2-year-olds
[90:58] um who were adopted.
[91:00] And uh and they studied the gut
[91:03] microbiome of these kids,
[91:05] and downstream they were able basically
[91:07] to identify that the fact that uh they
[91:10] came from an adopted home, even though
[91:12] it was before age two, like they can't
[91:14] remember this,
[91:15] even though uh it was before age two,
[91:18] the fact that they were from an adopted
[91:19] home, it affected their gut microbiome.
[91:22] It affected their response to stress,
[91:24] and it also affected the way that their
[91:26] brain works.
[91:27] And they actually were able to show this
[91:29] through functional MRI technology, where
[91:30] they looked at the brain and how it was
[91:32] how it was activating. Just because of
[91:34] that sort of early trauma? Early trauma.
[91:37] So, and not not, you know, not everyone
[91:39] who has gut issues has been exposed to
[91:41] trauma,
[91:42] but um I think it's important for people
[91:44] to understand that if you have been
[91:47] exposed to trauma, this can be a very
[91:50] important part of your healing process.
[91:51] That's the message that I want to get
[91:53] out into the world.
[91:54] And the reason why I bring that message
[91:55] is because I've had people who are in my
[91:57] clinic, and they're like, "Dr. B, I do
[92:00] everything that you tell me to do,
[92:02] and I do it by the book.
[92:04] I eat, I sleep, I exercise, I do yoga, I
[92:08] do meditate and I meditate."
[92:10] And despite that, they're not getting
[92:12] better.
[92:13] And in in those relationships, what ends
[92:16] up happening is typically after a couple
[92:18] of visits, we start to get comfortable
[92:19] with one another. We trust one another.
[92:22] And when you get to that place, they
[92:23] will share with me something that
[92:24] happened to them.
[92:26] And then I make it clear, this is the
[92:28] reason why.
[92:30] When you heal the wound of the trauma,
[92:32] you actually heal the gut. And it's
[92:33] amazing because they're like a rocket
[92:34] ship. Cuz they're doing all the right
[92:36] stuff, right? They're they're eating
[92:37] right, sleeping right, exercising.
[92:40] And the minute you take away this thing
[92:42] that is chaining them down
[92:44] and holding them back, the minute you
[92:45] release those chains, they shoot to the
[92:47] moon.
[92:48] And it's it's like the greatest thing to
[92:50] see, and I would say that like in my
[92:52] clinical career, that has been the most
[92:54] rewarding thing above anything else, far
[92:56] more than like getting a person to eat
[92:58] more fiber.
[92:59] What about alcohol? I've uh recently
[93:01] quit drinking alcohol. I'm glad you did.
[93:03] Why are you glad I did? Well, let me be
[93:05] the first to say that um I have not
[93:08] completely quit consuming alcohol, but
[93:11] if we remove my imperfect self from this
[93:13] picture and just look at the science,
[93:15] the science is actually quite clear. Our
[93:17] gut is damaged by alcohol. So, let's
[93:20] take a step back for a moment. If I want
[93:22] to clean this table, right? We're all
[93:24] done, we want to clean it up, what are
[93:25] we going to do? We pull out rubbing
[93:27] alcohol.
[93:28] It destroys microbes.
[93:31] Alcohol destroys microbes.
[93:34] And when we drink to the point of having
[93:36] a hangover, is that dehydration?
[93:39] Absolutely not.
[93:41] And I'm of the belief, based upon the
[93:43] research that I've seen, that what's
[93:45] happening when you're uh having a
[93:46] hangover is that you have caused
[93:49] significant damage to your microbiome.
[93:52] And this is the reason why it takes 24
[93:54] hours or more for you actually to start
[93:56] to feel like a human being again. What
[93:58] you see with alcohol is disturbing.
[94:01] It's more than just liver disease.
[94:03] There are many different health-related
[94:05] conditions that are tied back to alcohol
[94:07] consumption.
[94:09] And the thresholds that we've set, where
[94:11] we say people it's okay, like it's it's
[94:13] moderate alcohol if you have up to three
[94:15] drinks a day as a guy,
[94:16] or up to two drinks a day as a woman,
[94:18] like that to me is ridiculous. That's a
[94:20] lot.
[94:21] But the study that changed everything
[94:23] for me
[94:24] was where they actually monitored um
[94:27] levels of something called bacterial
[94:30] endotoxin,
[94:31] or lipopolysaccharide.
[94:33] This is something that is not supposed
[94:35] to be in our bloodstream.
[94:37] When it is in our bloodstream, it's
[94:39] because there's been damage to the gut
[94:40] barrier.
[94:42] And it causes inflammation.
[94:44] This is the exact same thing that can
[94:45] cause us to get extremely sick,
[94:48] but at a minimum, it is causing
[94:50] inflammation in your body.
[94:52] And um they did a study where they were
[94:54] basically monitoring
[94:56] levels of this lipopolysaccharide
[94:59] after alcohol consumption
[95:02] and in association with blood alcohol
[95:03] levels.
[95:05] And what they showed in the study is
[95:07] they were parallel lines.
[95:10] Blood alcohol level goes up,
[95:12] lipopolysaccharide level goes up.
[95:15] Blood alcohol level turns down,
[95:17] lipopolysaccharide level turns down.
[95:20] They were the exact same thing.
[95:22] So, when I saw that,
[95:24] to me,
[95:25] even when we're consuming minimal
[95:27] amounts of alcohol,
[95:28] we are potentially causing problems for
[95:30] our gut microbes.
[95:31] What is the brain-gut connection? So,
[95:33] the brain-gut connection is referring to
[95:35] the fact that um your gut's best friend
[95:37] is the brain.
[95:39] They're talking to each other right now,
[95:41] and they are inseparable. You can't get
[95:43] away from that.
[95:44] Um there's a number of ways that your
[95:46] gut will talk to the brain.
[95:48] So, part of it is the release of
[95:49] neurotransmitters.
[95:51] Uh 95%
[95:53] of the serotonin in your body is
[95:56] produced by the gut.
[95:58] Serotonin is the happy hormone.
[96:00] It's what makes us feel energized.
[96:02] Um it's what gives us great mood, and in
[96:05] some ways also also gives us focus.
[96:08] You would think that it comes from your
[96:10] brain, you know, when we treat a person
[96:11] with major depression,
[96:13] we treat them to increase serotonin
[96:15] levels.
[96:16] Yet only 5% of the serotonin in your
[96:18] body actually is produced inside your
[96:20] brain.
[96:21] 95% of it is produced within your gut.
[96:25] Serotonin can signal the brain
[96:28] through a nerve called the vagus nerve.
[96:31] The vagus nerve is like a super phone
[96:34] between the brain and the gut. It would
[96:35] be like uh if you were in London and I
[96:38] were in the United States, and I had a
[96:40] direct line to you where I just pick
[96:42] this up and I go, "Yo, Steven, I need to
[96:44] talk to you." Right? That's the way that
[96:46] this works. Your gut is talking to your
[96:47] brain directly on that phone line.
[96:50] So, serotonin,
[96:52] dopamine, 50% of dopamine, which is the
[96:54] reward hormone, produced in the gut.
[96:56] There are over 30 neurotransmitters
[96:57] produced in the gut. There's also the
[96:59] vagus nerve that we just talked about,
[97:01] and then finally,
[97:02] your gut is producing metabolites,
[97:05] postbiotics,
[97:06] that can cross into the brain and have
[97:09] an effect. We mentioned this earlier.
[97:11] Short-chain fatty acids from fiber have
[97:14] the ability to cross the blood-brain
[97:15] barrier and actually influence things
[97:17] like our mood, our focus. There was one
[97:20] study with kids
[97:21] where by increasing short-chain fatty
[97:23] acids for those kids, they actually were
[97:25] able to increase their focus because
[97:26] they were having trouble with focus.
[97:28] You've repeatedly talked about fiber and
[97:31] this thing you called short-chain fatty
[97:33] acids. In your book, you said I you
[97:34] believe that they're the most healing
[97:35] nutrient in all nature. I think that's
[97:38] actually true, and I also would um
[97:41] characterize them as the most
[97:42] anti-inflammatory
[97:44] molecule that I've ever come across. And
[97:46] am I right in thinking we eat fiber, the
[97:49] bacteria in our microbiome breaks down
[97:51] that fiber, and it produces this thing,
[97:54] these short-chain fatty acids? Is that
[97:56] it? That's that's I don't but
[97:59] just getting started, though. Okay.
[98:00] Yeah, the story's just getting started
[98:01] because the issue is that that's the
[98:03] simple part, right? These these
[98:05] magicians that live inside of us release
[98:06] these short-chain fatty acids for us. By
[98:08] eating fiber? By eating fiber or or
[98:10] resistant starches. Okay. But then um
[98:14] then those short-chain fatty acids go to
[98:15] work, and our our immune cells,
[98:19] our human cells, have receptors
[98:23] to receive these short-chain fatty acids
[98:25] and act upon the information that they
[98:27] receive.
[98:28] So, you could think of them as like a
[98:30] signaling molecule in the sense that
[98:31] your gut microbiome is now talking to
[98:33] your body and telling your body what it
[98:35] wants your body to do. So, it's training
[98:37] it. Yeah, but it has uh the ability to
[98:41] like flip genes off and on.
[98:43] Okay. It has the ability to turn down
[98:45] your immune system. So, as an example,
[98:47] when I think about autoimmune
[98:49] conditions,
[98:50] if we were to get like super into the
[98:52] details of of autoimmune conditions,
[98:54] what you would discover is that we need
[98:56] more short-chain fatty acids to empower
[98:59] these specific cells called T regulatory
[99:01] cells, and those T regulatory cells
[99:03] would actually turn down our immune
[99:04] system and protect us.
[99:05] Interesting.
[99:06] So, and I and it's not to say that
[99:07] autoimmune diseases are exclusively the
[99:09] result of a fiber deficiency.
[99:12] Um there is certainly a genetic
[99:14] component, but there was a genetic
[99:16] component 200 years ago, 300 years ago.
[99:18] And yet those these conditions really
[99:20] weren't that much of a problem back
[99:22] then.
[99:23] So, many of these conditions didn't have
[99:24] a name until the last 100 years.
[99:27] And um and the emergence of them, many
[99:29] of them have increased 500% in the last
[99:32] 50 years.
[99:33] Why would that be? It clearly is not
[99:35] genetics. So, it has to be related to
[99:38] our diet and lifestyle. And ultimately,
[99:40] when we talk about our diet and
[99:41] lifestyle, we're talking about our
[99:42] microbiome.
[99:44] And really the
[99:45] one of the most important places to
[99:46] start, as you say, is with the fiber. I
[99:48] think so. And you said earlier on we
[99:49] have to start slow and low with fiber.
[99:52] Yeah. And that's because we've got to
[99:53] build up those microbes that respond to
[99:56] the fiber and turn it into the
[99:57] short-chain fatty acids, right?
[100:00] Your gut is like a muscle.
[100:02] Right? Like this is this is the way that
[100:03] I want people to understand this. Your
[100:05] gut is like a muscle, and a muscle is
[100:07] capable of work.
[100:09] But it has limitations.
[100:11] And the more that the muscle has been
[100:13] trained, the more capable of work
[100:15] it is.
[100:17] So, if you um
[100:19] lift weights,
[100:20] you might start at
[100:23] 50 kilos.
[100:25] If we're doing a bench press, you might
[100:26] start at 50 kilos.
[100:28] And then you go to 55 kilos.
[100:30] And then the 60 kilos, and you work your
[100:32] way up, and that's the process of
[100:34] growing strong.
[100:35] And your gut works the exact same way.
[100:37] So, if you expose your gut to food,
[100:41] specifically a diverse mix of different
[100:43] foods,
[100:45] you are training your gut.
[100:46] And your gut will become more capable of
[100:48] consuming those foods over time.
[100:51] And then you can eventually get to a
[100:52] point where you don't have to then
[100:54] restrict based upon your capabilities,
[100:57] because the capabilities are limitless.
[101:00] Now, you can eat whatever you want.
[101:02] And is all fiber the same?
[101:04] No, not all fiber is the same. Fiber is
[101:06] a very generic word. Fiber is like the
[101:08] word protein. Mhm. No one would claim
[101:10] that the protein in a fish is the same
[101:12] as a protein in a bean. Yet both of them
[101:13] contain protein.
[101:15] Fiber is unique to individual plants.
[101:18] There are many, many different forms of
[101:20] fiber to the point that we don't even
[101:22] know how many exist. So, what we know is
[101:24] this. It's rather simple, though, right?
[101:26] Given that despite that complexity, it's
[101:27] rather simple. All plants contain fiber.
[101:32] Every single plant has unique forms of
[101:35] fiber.
[101:36] We do split it into two major types.
[101:39] These are again umbrella terms. These
[101:41] are big labels.
[101:43] Soluble and insoluble fiber.
[101:47] The soluble fiber is the kind that
[101:49] dissolves in a drink.
[101:50] It disappears. You don't even know that
[101:52] it's there.
[101:53] Yet typically, the soluble fiber is
[101:55] feeding the microbes. That's the
[101:56] prebiotic fiber.
[101:59] Insoluble fiber is the kind that's the
[102:00] grit.
[102:02] So, like if you were to add it to a
[102:03] drink, it's not dissolving. It's going
[102:04] to be there no matter what. You could
[102:05] boil the drink, there'd still be fiber
[102:07] in it.
[102:08] So, insoluble fiber most of the time
[102:11] is not the prebiotic fiber, but it does
[102:14] still serve a purpose.
[102:16] It helps in terms of your bowel transit,
[102:18] which affects your gut microbes.
[102:20] It helps in terms of your bowel
[102:21] movements,
[102:22] which affects your gut microbes.
[102:24] It helps in terms of other things, such
[102:26] as your cholesterol and your blood fat
[102:27] control.
[102:29] So, both types of fiber, both soluble
[102:31] and insoluble, have advantages. You
[102:33] don't need to worry about those
[102:34] individually.
[102:35] You just need to know that
[102:37] plants have fiber.
[102:39] Every single plant has unique form of
[102:40] fiber.
[102:42] And every single plant will feed unique
[102:44] families of microbes as a result of
[102:45] this. You have these F goals you talk
[102:47] about in the book when you're
[102:48] recommending diets that you think people
[102:52] should consider. And I think it's
[102:53] important cuz this word diet is quite
[102:55] stigmatized, right? And it can lead to
[102:57] like disordered eating and things like
[102:58] that. So, I think it's important for us
[103:00] to talk about that a little bit, but I
[103:01] do want to know what these F goals are.
[103:02] And when you use the word diet, you're
[103:04] not saying something that's
[103:05] unsustainable and short in order to have
[103:07] a short term goal.
[103:08] actually the opposite. Like I want
[103:09] people to have abundance. In fact, I
[103:12] would if you were to ask me, what is the
[103:14] biggest misconception that exists in the
[103:16] gut health space?
[103:17] My answer to that question would be that
[103:19] people are very quick to restrict
[103:22] and less quick to add back.
[103:25] So, with regard to F goals,
[103:27] um this is my general framework. It is
[103:29] not the like only thing, but this is my
[103:31] general framework for how I remember to
[103:34] organize my day in terms of foods that
[103:35] I'm trying to seek out.
[103:38] Each letter represents different
[103:39] categories of food. So, F, fruit.
[103:43] Um I think fruit has been
[103:44] inappropriately uh villainized. I think
[103:47] fruit's amazingly good for us. In fact,
[103:48] people that consume more fruit are less
[103:50] likely to have diabetes. They also lose
[103:52] weight.
[103:54] Fermented. Uh we've talked about
[103:55] fermented. You can add more diversity to
[103:57] your microbiome by adding fermented
[103:59] food. We need this.
[104:00] G, G stands for greens.
[104:03] Greens have almost no calories, yet tons
[104:05] of nutrition. That's good.
[104:08] And grains. By grains, I don't mean
[104:10] refined grains.
[104:12] I mean unrefined grains.
[104:14] So, like whole grains.
[104:16] So good for us. Those are gut microbiome
[104:18] foods, high in fiber and um resistant
[104:20] starches.
[104:22] O stands for omega-3 super seeds. So,
[104:24] that's chia, flax, hemp, and also
[104:27] walnuts.
[104:28] Um those contain omega-3 fats. Those are
[104:30] healthy fats that we need more of.
[104:33] A stands for aromatics. So, that's
[104:35] onions, garlic, shallots. They're
[104:37] delicious. They're also great for your
[104:39] heart and protect you from cancer.
[104:43] L is legumes. So, uh legumes includes
[104:46] beans, peas, and lentils.
[104:49] Um I would go back to saying like to me
[104:51] this is the number one.
[104:53] The number one superfood. Um because
[104:55] they're gut health foods, and they're
[104:56] longevity foods. And if we look at the
[104:58] evidence with heart disease, cancer,
[105:00] stroke, diabetes, all all across the
[105:03] board, you're going to see these reduce
[105:05] your likelihood of having those
[105:06] diseases.
[105:08] Um S, I when I got to S, I kind of lost
[105:10] my mind
[105:12] because I felt like I have more that I
[105:14] want to say, so let me just pack it all
[105:15] in. So, S stands for shrooms, meaning
[105:18] mushrooms.
[105:20] Um mushrooms technically are not plants.
[105:21] They're fungi.
[105:23] But they contain fiber and are
[105:25] incredibly good for us. So, they are
[105:27] honorary plants.
[105:28] Um S also stands for seaweed.
[105:32] So, most cultures don't consume seaweed,
[105:34] but like for example, in Japan, they do.
[105:36] And they are incredibly healthy as a
[105:38] result of this. It's another source of
[105:40] unique types of plants with unique
[105:41] sources of fiber.
[105:43] And the last is I'm going to in the
[105:45] book, I said sulforaphane,
[105:48] which refers to a cancer-fighting
[105:49] chemical that you will find in broccoli
[105:51] sprouts.
[105:52] But um I want to re- rephrase this to
[105:55] say sprouts.
[105:57] So, sprouts to me are superfoods.
[105:59] There's something magical that happens.
[106:00] What is a sprout, by the way, for people
[106:01] who are wondering?
[106:02] You can take any um
[106:05] any seed
[106:06] um
[106:08] and if you quite simply add water,
[106:12] you will unlock nature.
[106:15] Because basically that seed is waiting
[106:16] to germinate and grow.
[106:18] So, when you enter this code of
[106:20] basically like unlocking it with water,
[106:22] it comes to life. It opens up, and out
[106:25] shoots this plant.
[106:26] And that that plant is the sprout, and
[106:29] the sprout is tremendously high in
[106:31] fiber, protein, but also
[106:33] phytochemicals. There's unique chemicals
[106:35] that you will find in these plants in it
[106:38] in a disproportionate level compared to
[106:41] for example, you know, uh I mentioned
[106:44] broccoli sprouts. Broccoli sprouts have
[106:47] 50 to 100 times more cancer-fighting
[106:50] chemical
[106:52] than adult broccoli has. So, eating a
[106:54] pinch
[106:56] of broccoli sprouts can have you can
[106:58] provide just as much benefit as eating a
[107:00] head of broccoli.
[107:02] So interesting. So, if you're a parent
[107:04] and you follow the F goals diet that you
[107:06] lay out in your book, the interesting
[107:08] thing I find is if you're a mother and
[107:09] you're having a child, you're then going
[107:11] to pass on some of your microbiome to
[107:12] that child. And And also, I was reading
[107:14] about that mice study conducted um
[107:17] that shows how the Western diet induces
[107:20] a loss of microbial diversity that can
[107:22] compound over a series of generations.
[107:25] Yeah. It was a Justin Sonnenburg study.
[107:26] So, Justin Sonnenburg is a guy that I'm
[107:28] big fan of. He's out in Stanford, and he
[107:30] actually um wrote a blurb on my first
[107:32] book, Fiber Fueled.
[107:34] And
[107:35] so, um
[107:36] the issue is that we want to understand
[107:39] microbial loss that can occur over
[107:41] generations, because clearly our
[107:42] generation is different than our
[107:44] grandparents. Mhm.
[107:46] And it's hard to do with humans, because
[107:48] it takes us like, you know, these days
[107:49] 30 or more years to create a new
[107:51] generation.
[107:53] So, but with mice, you can do this very
[107:54] quickly. Mhm. So, he basically started
[107:57] off with mice with uh certain level of
[108:00] microbial diversity. Um
[108:03] the diversity of the microbiome is a
[108:04] measure of the health of their
[108:06] microbiome.
[108:07] And then he saw what happened with a
[108:10] And so, basically what he saw is that if
[108:12] you put them on a low-fiber diet, that
[108:14] mouse will start to lose diversity.
[108:17] And then it will transfer that onto its
[108:18] offspring.
[108:20] And then that offspring, who's still on
[108:21] a low-fiber diet, continues to lose
[108:23] diversity
[108:24] and transfer that onto their offspring.
[108:27] And so on.
[108:28] And what he found was that if during
[108:30] this process, you intervene and you add
[108:31] back the fiber,
[108:33] you can actually restore, on some level,
[108:37] the diversity within the microbiome. You
[108:38] can wake them back up. They can come
[108:40] back.
[108:41] But the issue is you won't get all the
[108:43] way back to the starting point.
[108:45] So, there is a certain level of loss
[108:46] that has taken place as a result of
[108:48] those choices that were occurring over
[108:50] generations. If your grandmother has
[108:52] 1,200 species of microbes in her gut as
[108:54] a child, but by the time your mother was
[108:56] born, she had 900,
[108:59] that's what your mother got. Yep.
[109:01] Then if your mother loses 300 species in
[109:03] her microbiome, now you start off with
[109:05] 600, half of what your grandmother
[109:08] originally had.
[109:09] Right. And at some point the loss of
[109:11] those species becomes problematic
[109:13] because um each of those species is
[109:15] there with a purpose. We evolved to have
[109:17] them. And when they're absent, they're
[109:19] not able to do their job.
[109:21] And the other microbes may not be able
[109:23] to step up to actually do what's the job
[109:26] of what's missing. It's just such a
[109:28] great case that, you know, keeping
[109:29] ourselves healthy is keeping our
[109:30] children healthy as well in many
[109:32] respects. And we also live with our
[109:33] children. So we're creating an ecosystem
[109:35] in our homes of
[109:38] these microbes
[109:39] on everything. I think that's completely
[109:41] true. And um and and I also think that
[109:44] like when we think about um
[109:47] generational issues that exist. So, you
[109:50] know,
[109:51] in many studies they'll say if your
[109:53] parents had this,
[109:55] then you're at risk for this.
[109:58] And we have assumed that these are
[109:59] genetic things.
[110:00] Yet much of the genetic research, much
[110:02] of which has been done by Tim Spector,
[110:04] uh my partner at Zoe,
[110:07] much of that has not played out to prove
[110:09] that it is in fact genetic.
[110:12] I think what's happening
[110:13] is not just the transfer of microbes. I
[110:16] think it's also the transfer of
[110:17] lifestyle.
[110:19] And the lifestyle that gets transferred
[110:21] by generation is um if it's unhealthy,
[110:25] then unfortunately you're transferring
[110:27] along the problems that come with that.
[110:29] Mhm. Interesting. So you're transferring
[110:30] the lifestyle and the microbes which
[110:32] when able to deal with the lifestyle
[110:33] that caused the disease. Right. So
[110:35] interesting.
[110:37] Sexual attraction is the last thing I
[110:38] want to talk to you about. Yeah. Sexual
[110:40] attraction and the the gut microbe. You
[110:42] you mentioned earlier sort of erectile
[110:43] dysfunction. There's pheromones. There's
[110:45] all of these sort of sexual components
[110:47] that lead us to having a great sex life.
[110:49] What is the link or the association
[110:51] between the gut microbiome and sex and
[110:55] erect good erections and desire and
[110:58] libido if any at all? First of all, I
[111:00] think it's quite clear that when people
[111:01] are sick, which of course they have a uh
[111:03] damaged gut microbiome. When people are
[111:05] sick, like they're not the libido is
[111:06] gone. Right? That's a part of that
[111:08] territory.
[111:10] Libido is also associated with hormones.
[111:13] And there's a number of different
[111:15] hormones that our gut microbes have the
[111:17] ability to impact. For women, estrogen.
[111:21] There's a term that's called the
[111:22] estrobolome.
[111:24] An estrobolome sounds a little bit like
[111:25] microbiome because basically what we're
[111:27] referring to are the microbes
[111:30] that control estrogen levels
[111:32] in women.
[111:34] So the gut microbiome create estrogen.
[111:36] It controls the recirculation of
[111:38] estrogen. Okay. So estrogen has this
[111:41] circular circular pattern. And in that
[111:43] circular pattern, it can basically be
[111:45] pooped out. Ah. Or it can enter back
[111:47] into the system. And the gut microbes
[111:49] are the gatekeepers. Ah. So they have
[111:51] the ability to actually control estrogen
[111:53] levels in the body on a certain level.
[111:56] This is the reason why if you look at
[111:58] estrogen-driven
[111:59] conditions, breast cancer. Breast
[112:02] cancer, uh ovarian cancer, endometrial
[112:04] cancer, endometriosis,
[112:07] what you discover is that in these
[112:08] conditions there's damage to the gut
[112:09] microbiome in all cases.
[112:12] So and there
[112:13] the it provides the suggestion, not yet
[112:15] proven, it provides the suggestion that
[112:17] damage to the microbiome may be fueling
[112:21] um
[112:22] alteration of these estrogen levels.
[112:25] All right. The same is also true with uh
[112:28] testosterone or androgens, male sex
[112:31] hormones, which by the way of course all
[112:33] men have estrogen. And all women have
[112:36] male sex hormones as well. It goes both
[112:38] ways. It's just the dominance
[112:40] between the two genders.
[112:42] So there's a bacteria called Clostridium
[112:44] scindens that's been known to basically
[112:47] affect male testosterone levels.
[112:49] Um so and there are conditions, for
[112:51] example, polycystic ovary syndrome in
[112:53] women that it's the um imbalance
[112:57] between the estrogen
[113:00] and the androgens that's strongly
[113:02] associated with the manifestation of
[113:03] this condition, polycystic ovary
[113:05] syndrome.
[113:06] And we suspect that the gut is central
[113:08] to this. Okay. So, first of all,
[113:11] hormonal the first point is that
[113:12] hormonal related issues are connected
[113:14] back to our gut microbes.
[113:16] All right. So, libido, sex, like these
[113:19] things obviously have a hormonal element
[113:21] to them. And this is the reason why
[113:23] erectile dysfunction or uh I'm quite
[113:26] sure not as well studied because it's
[113:27] not as easy to provide like a diagnostic
[113:29] label to this, but female sexual desire
[113:33] I'm quite sure would also be associated
[113:34] with the gut microbiome. I'm quite I'm
[113:36] almost positive of this.
[113:38] The question that I come back to that I
[113:39] find to be very interesting is that the
[113:41] rule is the rule that the microbes play
[113:43] in matchmaking.
[113:47] Between two human beings. Between two
[113:48] human beings.
[113:49] Making me attracted to another human.
[113:51] Yes. So and I come back to basic
[113:53] question. So now look, I've been married
[113:55] for 10 years. Um so it's been a long
[113:57] time since I've been a single guy, but I
[113:59] but I think we can all relate to you've
[114:01] been on a date
[114:02] and there was something not not
[114:04] personality, there was something about
[114:05] the person
[114:07] perhaps the smell that you noticed
[114:10] that you're just like this is a turnoff.
[114:12] This is not going to work.
[114:14] Right? Or it could be in the way that a
[114:16] person kisses.
[114:18] And these compatibility issues I'm
[114:21] convinced actually come back come from
[114:23] the gut microbiome. That they are in a
[114:24] way matchmakers and that we're looking
[114:26] for good partners. I can't put my finger
[114:28] on exactly what that means. What makes a
[114:31] good partnership?
[114:33] But we do know that that partnership we
[114:34] discussed earlier ultimately has an
[114:36] effect on your gut microbiome because
[114:38] you're going to share.
[114:40] I I am convinced that sexual attraction
[114:42] is brought back to these things. And in
[114:43] animal studies, it's harder to do in
[114:45] humans,
[114:46] but in animal studies they have actually
[114:48] discovered that the pheromone levels,
[114:50] how you smell, your sort of like, you
[114:53] know, hey, attractiveness hormone
[114:55] is connected back to the gut microbes.
[114:57] So kissing is connected to the gut
[114:58] microbes, pheromones are connected to
[115:00] the gut microbes, sexual desire and
[115:03] libido and uh male erection are
[115:06] connected to the gut microbes. Um I
[115:08] don't know where the line exists where
[115:10] it would stop. I think it's all
[115:11] connected. Okay. So if I want to be more
[115:13] attractive, do I just need to eat some
[115:14] sprouts? What what what are you saying
[115:16] here?
[115:17] Because it is it about compatibility or
[115:19] is it about gut health?
[115:22] I think that it's very clear. So,
[115:25] um
[115:26] attraction is a complex thing. Of
[115:27] course.
[115:29] We all have a different take. You know,
[115:32] I mean I have friends who there's
[115:33] someone that they find attractive. To me
[115:35] it's completely different for me. Right.
[115:37] And and that's all like uh that's good.
[115:39] Like I'm glad that we have a different
[115:40] take because variety is necessary in
[115:43] terms of the genetic pool. Right? Like
[115:44] we need everyone different people to
[115:46] want different things.
[115:48] That being said,
[115:50] I I I kind of feel like
[115:54] the um
[115:56] there are certain innate qualities
[115:59] in a person
[116:00] that we would universally agree are
[116:02] attractive. Mhm.
[116:04] And those tend to be measures of health.
[116:06] We usually think Yeah, you're right.
[116:07] Yeah. Yeah. Cuz I was going to say we
[116:09] think of them as physical things, right?
[116:11] Um things we can see with our eyes
[116:13] typically or things we can consume with
[116:15] maybe our ears, you know, jokes or humor
[116:17] or wit or personality or whatever.
[116:20] But it's
[116:22] it's completely plausible that there is
[116:24] invisible things. Well, I don't think
[116:27] that the visible things can be
[116:28] disconnected from the invisible things.
[116:30] And that's one of the messages from the
[116:32] show today is that even the way that you
[116:35] look, the radiance of your skin,
[116:37] um your youthful appearance,
[116:40] um your uh your body shape. And there's
[116:42] many forms of body shapes that are
[116:44] attractive. I mean I'm not um
[116:46] saying that there's only one, but the
[116:49] um these are manifestations of what's
[116:51] happening on the inside.
[116:53] Would you recommend supplements? I know
[116:55] you've
[116:56] you've produced your own supplement
[116:58] which I have here. And I've actually
[116:59] been drinking as we've been talking. Um
[117:01] called 38 Tera, is it?
[117:03] 38 Tera. And 38 Tera, what that means is
[117:06] 38 trillion. So this is in reference to
[117:08] the 38 trillion microbes that live
[117:10] inside of us. And this particular
[117:12] product is called Daily Microbiome
[117:13] Nutrition.
[117:14] So in this product we are using specific
[117:17] ingredients at specific doses that have
[117:20] been clinically proven to have an effect
[117:22] and to have a benefit for your body.
[117:24] That includes things like improving your
[117:26] gut microbiome. It also means improving
[117:28] your bowel movements. We talked about
[117:29] going from a Bristol one or two or a
[117:31] Bristol six or seven back to a Bristol
[117:33] four. That's what I'm talking about
[117:35] right now.
[117:36] But also reducing digestive symptoms. Um
[117:39] so these are the benefits that we would
[117:40] get from regular use of a prebiotic.
[117:43] It's easy.
[117:44] It's a powder. You've been drinking it.
[117:47] I think it tastes pretty good. I don't
[117:48] know what you think. I was shocked.
[117:50] Yep. And it was so delicious. Yeah,
[117:52] refreshing. I've actually finished it
[117:54] all. I had it started the interview with
[117:55] it in this bottle here and it's all
[117:56] gone. Where does Where do people find
[117:58] this 38 Tera? 38 Tera is available at
[118:00] our website. So you come to 38 Tera,
[118:03] 38tera.com.
[118:06] And um and we are launching in
[118:08] mid-January for the first time. We're
[118:11] launching in the US and Australia.
[118:13] So in the UK it may be more difficult to
[118:15] get access to, but just uh
[118:18] be aware that if there's enough of a
[118:19] demand, then we would serve that demand.
[118:22] But if I if I am in the UK, I can still
[118:24] order it. There would just be probably
[118:25] shipping costs and stuff like
[118:26] Yes, there's a shipping cost.
[118:27] Okay.
[118:28] Super interesting. I I've learned so
[118:30] much today and it's crazy cuz I didn't
[118:31] think I had much else to learn about the
[118:33] gut microbiome. We've had lots of
[118:35] conversations about it, but it's really
[118:37] it's inspired me, it's informed me, and
[118:40] it's given me a sort of actionable
[118:41] blueprint to start taking action in my
[118:43] life.
[118:44] And if I were to just to close that out,
[118:46] you know, what are the takeaway messages
[118:48] for everyone?
[118:49] Eat a wide variety of plants.
[118:50] Mhm. Fruits, vegetables, whole grains,
[118:53] seeds, nuts, legumes, every single one
[118:54] of these counts.
[118:56] Coffee counts? Great. Absolutely. So add
[118:59] of more variety to your diet. Um add
[119:01] fermented food to your diet, get outside
[119:03] and exercise, get a good night's rest,
[119:06] hug that person that you care about,
[119:08] focus on human connection. Like, these
[119:10] to me are where the priorities are at.
[119:12] Many of these things, by the way, are
[119:13] completely free.
[119:16] We have a closing tradition on this
[119:17] podcast where the last guest leaves a
[119:18] question not knowing who they're going
[119:19] to be leaving it for.
[119:21] And the question that has been left for
[119:22] you, when have you been happiest in your
[119:25] life? You may define happy in any way
[119:29] you like.
[119:31] Happiness is,
[119:32] uh, I think what really matters. And we
[119:36] uh, I think we have a problem in today's
[119:38] world of excessively fixating on the
[119:39] objective things, like like money,
[119:42] and losing track of the things that are
[119:44] less measurable. I have no clue how
[119:46] happy you are at home. I have no clue,
[119:48] right? I have an idea of where you're at
[119:49] financially.
[119:52] Yet, this is where, um, the essence of
[119:54] life is.
[119:56] And to me, my my happiness comes from my
[119:58] family.
[119:59] It's the side of me that you wouldn't
[120:01] know unless you like literally were
[120:04] my friend in Charleston, South Carolina
[120:06] and spending time with me, the real
[120:07] person,
[120:08] right? But, um, regardless of what you
[120:11] see on this camera or hear on this
[120:13] episode,
[120:14] um, we are real people with real lives.
[120:16] And to me, my happiness comes from the
[120:19] pursuit of things with my family, um,
[120:22] doing everything within my power to
[120:24] fight for them,
[120:25] and also just to enjoy time with them.
[120:27] That's what it's about.
[120:29] That's a beautiful answer. Thank you so
[120:31] much, Dr. Will. You, um,
[120:33] you have a remarkable ability to
[120:34] communicate, but also you have a wealth
[120:36] of knowledge that is unrivaled as it
[120:38] relates to the issues we're talking
[120:39] about today. And it's really, really
[120:41] incredible. You're really, really
[120:42] incredible. And you're doing so much
[120:44] fantastic work for so many people
[120:45] because
[120:46] it wasn't until a couple of years ago
[120:48] that I learned about the gut and
[120:49] microbiome. And I know because I can see
[120:51] the data that it that the society at
[120:54] large are on a journey of now
[120:55] understanding the gut more and more. And
[120:56] the research that's coming out every
[120:57] year is pushing us closer to that
[120:59] understanding. And that understanding
[121:01] will unlock the things that we're all
[121:02] aiming for in our lives, which culminate
[121:03] in what you said there, which is
[121:04] happiness.
[121:06] So, that's the work you're doing. You're
[121:07] increasing public happiness, and I think
[121:09] that's, um, that's something that's an
[121:11] incredibly worthy mission. So, I thank
[121:12] you for that on behalf of all the people
[121:14] that are listening today that got to
[121:15] this part of the conversation and that
[121:17] don't have a a means of reaching you
[121:19] directly, thank you on behalf of all of
[121:21] us.
[121:22] Thank you. This uh, I'm
[121:24] honored to become on the show with you.
[121:25] And for people who want to continue that
[121:27] conversation, this is why I put things
[121:29] out into the world. And you can find me
[121:31] on social media as The Gut Health MD,
[121:33] Instagram, Facebook. I am on TikTok, but
[121:36] I think a 14-year-old stole my handle.
[121:38] Uh, happens. So, The Gut Health MD
[121:40] underscore is how you'll find me there.
[121:42] But, also you can come to my website,
[121:43] theplantfedgut.com.
[121:45] Sign up for my free email newsletter.
[121:46] That's where how I communicate the like
[121:48] I think the most effectively. Like, I
[121:49] break down studies there. So, come sign
[121:51] up for my email newsletter. And if you
[121:53] want to check out 38 Tera, you can learn
[121:55] more there as well. I'm going to put
[121:56] everything in the show notes. I'm also
[121:58] going to put in the show notes, which is
[121:59] the first time I've ever done this, I'm
[122:01] going to put the brief for this
[122:03] conversation in the show notes. And what
[122:05] the brief is, it's essentially all of
[122:06] the research my team did, and they
[122:08] condense it down into about 10 pages.
[122:11] And I think that's really important cuz
[122:13] we've covered so much ground here today
[122:15] that someone just listening, someone who
[122:17] had was having like a second screen
[122:19] experience or was doing the dishes or on
[122:20] the tube or whatever, there's a lot
[122:22] there.
[122:23] The 10 pages you'll find in the show
[122:24] notes summarize this conversation, the
[122:26] key takeaways, and the actionable
[122:27] insights. And this is something I'm
[122:29] actually going to start doing on an
[122:30] ongoing basis. Um, also the materials we
[122:33] discussed in this conversation, like the
[122:35] Bristol stool chart, and all of the
[122:36] other information that you talked about,
[122:38] which we'll pull from you after this
[122:39] conversation, will be in the show notes,
[122:41] including links to find Dr. Will
[122:43] everywhere on social media and on his
[122:45] website. Amazing. That sounds so cool.
[122:47] Can't wait to check that out.
[122:53] As you guys know, I'm a big fan of Huel.
[122:55] I'm an investor in the company, and they
[122:56] sponsor this podcast. And what I've done
[122:58] for you is I've put together, for those
[123:00] people that haven't yet tried Huel, but
[123:02] for all of those also that have but
[123:04] haven't tried my favorite products, I've
[123:06] put together what I call the Huel Steven
[123:08] Bundle, which is a selection of my
[123:10] favorite products from Huel, including
[123:12] the Black Edition Salted Caramel flavor,
[123:14] which is super high in protein and has
[123:16] 17 servings per container. The bundle
[123:18] also comes with their ready-to-drink
[123:20] product, which is one of my all-time
[123:22] favorite products from Huel. It is
[123:24] convenient, it is nutritionally
[123:25] complete. days where my life just gets
[123:27] very, very busy, it is my go-to product.
[123:30] Got your Huel bars, which are absolutely
[123:31] gorgeous. And in there you also get this
[123:33] incredible T-shirt, which is apparently,
[123:35] according to lots of my friends, the
[123:37] best quality T-shirt they've ever had.
[123:38] And I don't really know why, but there's
[123:39] something about this T-shirt that's
[123:40] incredibly flattering.
[123:42] This Huel shaker, the link is in the
[123:44] description below. In this podcast
[123:46] episode, wherever you're listening to
[123:47] it, there'll be a Steven's bundle link,
[123:49] and check it out.
[123:51] Do you need a podcast to listen to next?
[123:53] We've discovered that people who liked
[123:55] this episode also tend to absolutely
[123:58] love another recent episode we've done.
[124:00] So, I've linked that episode in the
[124:02] description below. I know you'll enjoy
[124:04] it.
