“95% of Serotonin is Made in the Gut!” How The Food You Eat is Tied to Anxiety & Depression

In this insightful conversation, Dr. Will Bulsiewicz, a board-certified gastroenterologist and New York Times bestselling author, dives into the profound connection between gut health and mental well-being. Emphasizing the gut's role in producing 95% of serotonin and housing 38 trillion microbes, Dr. Bulsiewicz explains how our gut microbiome significantly influences our mood, cognitive functions, and overall health. He advocates for a diverse plant-based diet, regular exercise, deep breathing exercises, and addressing emotional trauma to support gut health and, by extension, improve energy levels, mood, and various physiological processes. Dr. Bulsiewicz's approach to health is holistic, considering the intricate interplay between physical, emotional, and microbial factors in achieving optimal wellness.

• Serotonin is predominantly produced in the gut, not the brain.
• A personal anecdote from speaker A highlights the transformative health benefits of realizing the gut's role in serotonin production.

"Turns out that 95% of serotonin is produced not in your brain, in your gut."

The quote emphasizes the surprising fact that the majority of serotonin, a key neurotransmitter associated with mood and well-being, is produced in the gut rather than the brain.

• Dr. Will Bulsiewicz is introduced as a board-certified, award-winning gastroenterologist and a two-time New York Times best-selling author.
• He is recognized for his expertise in the microbiome.

"A board certified, award winning gastroenterologist, two time New York Times best selling author, the man with the master plan for the microbiome, doctor Will Bolshowitz."

The quote introduces Dr. Will Bulsiewicz, highlighting his credentials and expertise, particularly in the area of the microbiome.

• Humans have about 38 trillion microbes, outnumbering human cells.
• The human body is less than 50% human on a cellular level.

"We got 38 trillion microbes. Now. This is, by the way, more than we have human cells."

This quote points out that the number of microbial cells in the human body surpasses the number of human cells, indicating that we are largely composed of microbes.

• The number of daily bowel movements was briefly touched upon, but not elaborated.

"How many times should we be pooping a day?"

The quote presents a question about the normal frequency of bowel movements, suggesting an interest in digestive health.

• Inflammation in the gut can influence anxiety and depression.
• Emotional and psychological healing is essential for overall well-being.

"Inflammation influences anxiety and depression."

The quote establishes a link between gut inflammation and mental health issues such as anxiety and depression.

• Gut microbes play a role in various conditions, including mental health disorders.
• The microbiome consists of living microorganisms that are part of the human body.

"But I think that the important point, though, that the listeners need to hear is that they do play, these gut microbes do play a role."

This quote acknowledges the significance of gut microbes in affecting various aspects of human health, including mental health.

• Microbes exist on all external surfaces of the body, including the skin and eyes.
• The intestines, while inside the body, are considered an external surface due to the continuous nature of the digestive tract.

"There are 38 trillion microorganisms that exist, covering all external surfaces of our body."

The quote explains that a vast number of microorganisms cover every external surface of the human body, highlighting the extensive presence of the microbiome.

• The intestines are a continuous tube from the mouth to the anus and are technically outside the body.
• The immune system is largely situated in the intestinal walls due to constant interaction with external factors.

"Your intestines are a continuous tube. It starts at your mouth. Now, you're a tall guy, much like me, okay? But the average person in the United States, somewhere between 20 and 28ft, okay."

The quote describes the intestines as a continuous tube, emphasizing its length and its role as an interface with the external environment.

• Humans have fewer human cells compared to microbial cells.
• Excluding red blood cells and platelets, humans are about 90% microbial.

"So we are less than 50% human."

This quote succinctly summarizes the concept that the human body is composed of more microbial cells than human cells, challenging the notion of what constitutes the human body.

• Microbes colonize the body after birth, starting with exposure during labor and delivery.
• Microbes have existed for billions of years and are integral to human physiology.

"The water breaks, mom goes into labor, and for the first time, the baby is exposed to the outside world."

The quote describes the initial colonization of microbes in the human body, which begins at birth.

• The human genetic code is less than 1% human when considering the genetic material of microbes.
• Humans are considered superorganisms due to the integration of microbial and human cells.

"And then if we were to talk about your genetic code, you are less than 1% human."

The quote highlights the overwhelming presence of microbial genetic material compared to human genetic material in the body.

• Microbes are concentrated in the colon and influence digestion, nutrient access, immune system, metabolism, hormones, and brain function.
• The gut-brain connection is bidirectional, with constant communication between the two.

"Our gut brain connection. And we can unpack this to describe the multiple ways that those microbes are communicating to our brain."

The quote points to the complex relationship between the gut and brain, mediated by microbes, and how they influence each other.

• A healthy brain is dependent on a healthy gut.
• The microbiome's health impacts the entire body, including cognitive functions and long-term health.

"To have the healthiest brain possible, it is essential to have a healthy gut."

The quote asserts the necessity of gut health for optimal brain function, emphasizing the interconnectedness of the two.

• Diet, specifically the diversity of plants, is crucial for improving mental health symptoms.
• The microbiome can be shaped by dietary choices, affecting overall health.

"What are three things they could do to start recognizing how to fix them?"

The question in the quote prompts discussion on actionable steps to address mental health symptoms through gut health.

• Diversity of plants in the diet is the most important factor for a healthy gut.
• Aiming for 30 different plants per week is recommended.
• Real, unprocessed foods like fruits, vegetables, whole grains, seeds, nuts, legumes, and mushrooms are advocated.

"The diversity of plants in your diet was the number one factor in predicting who had the healthiest gut."

The quote from a study reinforces the importance of plant diversity in the diet for a healthy gut microbiome.

• Ultra-processed foods lead to dysbiosis and a contracted microbiome.
• Microbiome diversity is key to preventing inflammation and associated cognitive and mood disorders.

"When we shift towards ultra processed foods, we're actually contracting the microbiome. We're empowering the ones that love sugar, we're empowering the ones that create inflammation."

The quote explains the negative impact of ultra-processed foods on the microbiome, leading to an increase in inflammation and harmful microbes.

• The microbiome may influence taste buds and cravings.
• Changing the microbiome can alter cravings towards healthier food options.

"There are interesting studies to suggest that our taste buds and our cravings are driven by our microbiome."

The quote suggests that the microbiome has a role in shaping our food preferences and cravings, which can be modified over time.

• Sustainable changes in diet are preferred over drastic switches.
• Consistency and enjoyment are key to reshaping the microbiome and changing taste preferences.
• Four weeks of consistent healthy eating can start to change taste buds, with longer periods leading to more profound changes.

"So I say four weeks is what it takes to really make this huge change. But really, I would rather that you do it over the course of six, six months, a year."

The quote advises a gradual approach to dietary changes, emphasizing the time required for significant shifts in the microbiome and taste preferences.

• The gut microbiome plays a significant role in various health conditions.
• Conditions like heart issues, energy levels, and mental focus are influenced by the state of the microbiome.
• Improvement begins with dietary changes, specifically increasing the variety of plants in the diet.

"And basically what I'm saying is the gut microbiome is a player in all of these different conditions." "And the way that that starts is by changing. Changing your diet."

• The quote highlights the importance of the gut microbiome in different health conditions and suggests that dietary changes are the starting point for improvement.

• The SMILES trial indicated that a plant-predominant Mediterranean diet could be as effective as medication for treating major depression.
• The focus is on dietary abundance rather than restriction, emphasizing the addition of diverse plant foods.

"Where they took a plant's predominant, not, it was not vegan, it was a plants predominant Mediterranean diet." "And it was as effective as medication for the treatment of major depression."

• The quote discusses the effectiveness of a plant-predominant Mediterranean diet in treating major depression, comparable to medication.

• Exercise improves mood and can help in the treatment of major depression.
• Different exercises shape the microbiome in different ways, contributing to overall health and mood.
• Strength training and diverse physical activities, including athletic movements, are beneficial for the microbiome.

"So exercise clearly improves our mood, can be used as something to help in the treatment of major depression." "And one of the answers to that question is actually through the way that exercise shapes our microbiome."

• The quote explains that exercise not only improves mood but also shapes the microbiome, which has implications for treating depression.

• Studies on marathon runners and rugby players revealed specific beneficial bacteria in their microbiomes associated with their physical activities.
• These bacteria, such as vellonella and anti-inflammatory bacteria, help with endurance and recovery by breaking down lactic acid and producing short-chain fatty acids.

"They did this study where they looked at marathon runners. And they identified that there was this one bacteria called vellonella that was disproportionately represented within these marathon runners." "They discovered that there was a shift within their microbiome towards actually more anti-inflammatory bacteria."

• The quotes describe research findings on how specific types of exercise are associated with the presence of beneficial bacteria in athletes' microbiomes.

• The microbiome is intricately connected to mood, with studies showing that interventions affecting the microbiome can influence mood and behavior.
• Injections of lipopolysaccharide, a component from E. Coli, into human subjects caused increased inflammation, mood dips, and social withdrawal, simulating the effects of a damaged gut.

"They have these bizarre studies that they've done where they take people and they inject into them something called lipopolysaccharide." "And they see what happens, and here's what they find. Number one, because this bacteria has entered into the bloodstream, they get increased levels of inflammation in the body. Number two, their mood and their motivation to work dips."

• The quotes discuss the direct impact of gut-related substances on human mood and behavior, illustrating the connection between the microbiome and mental health.

• Correlation between damaged microbiomes and depression is observed, but causation is challenging to prove.
• Interventions like the lipopolysaccharide study help to simulate the effects of a damaged gut, suggesting a causal relationship between gut health and mood.

"You have a group of people with major depression and you study their microbiome and you discover that their microbiome is damaged." "And there's a couple of ways that you prove this through interventions."

• The quotes address the challenges in establishing causation between microbiome health and depression, highlighting the use of interventions to simulate the effects of gut health on mood.

• Speaker A shares a personal journey of dealing with depression and poor health despite professional success.
• The turning point came from changing dietary habits, which led to improved health and self-esteem.
• This personal transformation motivated Speaker A to incorporate dietary changes into clinical practice, leading to positive patient outcomes.

"And one of the issues that I had was I was depressed." "Making that change completely radically transformed my health."

• These quotes reveal the personal experience of Speaker A with depression and how dietary changes profoundly impacted their health and professional approach.

• The vagus nerve is a critical pathway for communication between the gut and the brain.
• It is connected to the gut and senses changes in the immune system, relaying information back to the brain.
• Techniques like deep breathing exercises can activate the vagus nerve, influencing mood and health.

"And the vagus nerve is absorbing information. It is sensing what is happening within our gut with our immune system and communicating that back to our brain." "So deep breathing exercises affect the vagus nerve."

• The quotes explain the function of the vagus nerve in gut-brain communication and offer a practical method for influencing it through deep breathing exercises.

• Studies consistently show benefits of controlled breathing with approximately 4 seconds in and at least 4 seconds out.
• The speaker advocates for 6 seconds out due to a specific study.
• Controlled breathing is better than shallow chest breathing and helps fully oxygenate the body and brain.
• This type of breathing activates the vagus nerve, which connects the gut to the brain, potentially improving both areas.
• Daily practice of this breathing for ten minutes can lead to noticeable differences over time.

"So I'm talking about 6 seconds out just because of this one study."

This quote indicates the speaker's preference for a longer exhale based on research findings.

"All of that and then activating the vagus nerve. That's what we're getting at."

The importance of the vagus nerve in the context of controlled breathing is highlighted here.

"And if you do it for literally ten minutes, literally ten minutes, you will notice differences as you start to do this day by day."

The speaker emphasizes the short daily commitment required to see benefits from this practice.

• Controlled breathing exercises have been shown to improve bowel motility and frequency, particularly in those with constipation.
• A study involving individuals with irritable bowel syndrome with constipation showed that breathing exercises alone could relieve constipation.
• These improvements occurred without dietary changes or laxatives, illustrating the power of breathing exercises on intestinal physiology.

"And what they discovered is that it actually radically transformed their bowel motility."

This quote summarizes the impact of breathing exercises on bowel function from a study.

"They pooped better. Now, if you exercise, you'll poop even better. If you eat fibro, you'll poop a hell of a lot better. But, wow."

The speaker acknowledges additional factors like exercise and diet that can further enhance bowel movements.

• The speaker believes in the importance of complete and satisfying bowel movements.
• Frequency of bowel movements can vary; the focus should be on the quality and completeness rather than the number.
• The speaker indicates that a fiber-rich diet could lead to more frequent bowel movements, potentially more than once a day.
• The speaker warns against fixating on frequency, as individual bowel movement patterns can differ and still be healthy.

"If you are pooping on a level where you have complete, adequate bowel movements, it's satisfying. You have a sense of relief when you're done and you are not suffering symptoms as a result of your bowel movements during a great place."

This quote stresses the importance of the quality of bowel movements over their frequency.

• The speaker advises against spending more than five minutes on the toilet to avoid hemorrhoidal issues.
• A proper pooping position involves elevating the feet, which can be achieved with devices like the Squatty Potty.
• The urge to defecate should be listened to, and bowel movements should be natural and not forced.

"I prefer for people to have a natural bowel movement in five minutes or less. You shouldn't have to strain to go."

This quote emphasizes the ideal duration and ease of a healthy bowel movement.

• The speaker discusses the importance of chewing food properly for gut health and suggests that a diet with whole, less processed foods is generally better.
• There is evidence that the way food is served and consumed (e.g., whole vs. pureed) affects metabolism and the microbiome.
• The speaker advises against a raw food-only diet, suggesting that cooked foods and smoothies can be a gentler way to transition to a healthier diet.

"An intact food matrix is, generally speaking, the preferred way to consume our food."

This quote highlights the importance of consuming less processed foods for better health outcomes.

• Gut transit time, measured by the time it takes for food to pass through the digestive system, can be indicative of gut health.
• Fast transit times are associated with diarrhea, while slow transit times are linked to constipation.
• Both extremes of transit time are correlated with changes in the microbiome and can impact metabolic health, including cardiovascular risk.

"All of these things are actually correlated, not just to our microbiome, because they are, but they're also correlated to metabolic parameters."

The speaker connects gut transit time with broader health implications, including the risk of cardiovascular disease.

• Leaky gut syndrome is associated with a breakdown of the epithelial barrier and can lead to systemic inflammation and fatigue.
• The speaker suggests that energy levels are a measure of inflammation and immune system function.
• Chronic inflammatory conditions and autoimmune diseases are strongly linked to low energy and fatigue, indicating a possible connection to gut health.

"Energy is this thing that we all experience... and I'm here telling you that there's now overwhelming evidence that this is a measure of our inflammation."

The quote connects subjective feelings of energy with objective measures of inflammation and gut health.

• The gut produces a significant amount of neurotransmitters, including serotonin, which affects mood.
• Gut microbes influence the production of serotonin and its precursors, which can impact both gut motility and mood.
• The speaker discusses the connection between conditions like irritable bowel syndrome and changes in neurotransmitter levels.

"95% of serotonin is produced. Not in your brain, in your gut."

This quote highlights the surprising fact that the majority of serotonin is produced in the gut, not the brain, and underscores the importance of gut health for overall well-being.

• Individuals with IBs disproportionately suffer from mood disorders.
• There is a high prevalence of depression, anxiety, and other mood disorders among people with IBs.
• The connection between the gut and the brain is a crucial aspect in understanding IBs.

"And in an overwhelming fashion, they suffer from mood disorders. There is a massive disproportionate prevalence of depression, anxiety, and other mood disorders and people that have IB's."

• This quote highlights the significant correlation between intestinal bowel syndromes and mood disorders, emphasizing the need for a comprehensive understanding of the gut-brain axis.

• The treatment approach for IBs has evolved to a more holistic view.
• It is now recognized that IBs are not just a digestive disorder but also a disorder of the brain-gut axis.

"Treating about IB's right now, there's a more holistic view, which is a good thing."

• The quote indicates a shift in perspective towards treating IBs, acknowledging the interconnectedness of the digestive system and mental health.

• The nervous system's response to feeling unsafe or being in an unhealthy relationship can impact gut health.
• The environmental and relational stressors can affect the digestive system through the nervous system.

"This is a disorder of the brain and gut axis."

• This quote reinforces the concept that IBs involve both the digestive system and the brain, necessitating a treatment approach that considers both aspects.

• Acute stress can lead to gastrointestinal symptoms like nausea, cramping, and the need to use the restroom.
• The sympathetic nervous system is activated during stress, which can negatively impact the gut microbiome and bowel motility.
• Chronic stress, such as unresolved trauma, can lead to chronic digestive disorders like IBs, Crohn's disease, and ulcerative colitis.

"The brain releases a hormone called corticotropin releasing hormone, or CRH. And the CRH sets off this inflammatory cascade and downstream. If you follow that, ultimately what you discover is it has a negative impact on the gut microbiome."

• This quote explains the biological mechanism by which stress influences gut health, highlighting the release of CRH and its downstream effects on the gut microbiome and inflammation.

• Emotional wounds and trauma can be root causes of digestive disorders.
• Addressing and healing emotional trauma can lead to significant improvements in digestive health.
• Building a doctor-patient relationship and bringing awareness to the connection between past trauma and current health issues is crucial.

"My proudest moments are taking that person who has been to six or seven doctors, and they're not getting better, even with medication. And you build a doctor patient relationship, it's not one visit talking about four, five, six visits, and you get to a place where they tell you something from their past that is still affecting them today."

• The quote emphasizes the importance of a trusting doctor-patient relationship in uncovering and addressing the emotional factors contributing to a patient's health issues.

• Healthcare professionals play a critical role in helping patients address and heal from emotional trauma.
• The healing process can lead to a transformation in the patient's overall well-being.
• Addressing emotional trauma can be the key to unlocking improvements in physical health.

"They turn towards that. And they have a healthcare professional, not me, that's not what I do, but they have a healthcare professional who helps them to heal that wound."

• This quote acknowledges the role of specialized healthcare professionals in guiding patients through the emotional healing process, which is integral to their physical recovery.

• Personalized dietary plans can be more effective than general dietary guidelines.
• The microbiome is unique to each individual, and understanding it can lead to better health outcomes.
• The Zoe study demonstrated that a personalized approach to nutrition significantly outperformed general dietary recommendations.

"We looked at the people who are most compliant with Zoe versus people who are most compliant with the government guidelines. Like, do you actually follow the advice? And when we compared those two things, Zoe dominated."

• The quote reveals the findings of the Zoe study, which showed the superiority of personalized nutrition plans tailored to individual needs over generic dietary guidelines.

• Investing in human connections and making time for family and loved ones is essential.
• Love and relationships are more fulfilling than material possessions or achievements.

"Make sure that you make time for your family and the people that you love. Because at the end of the day, all these things, the money is seductive, it's attractive. But it's love, it's relationships, it's family that really are what make us feel full."

• This quote conveys the message that nurturing relationships and prioritizing loved ones are crucial for a fulfilling life, beyond material success.

• There is optimism in the scientific revolution, especially regarding the microbiome.
• Small, consistent choices can have a significant impact on health and the microbiome.

"The choices that you make today will have an effect on your microbiome by tomorrow."

• The quote encourages optimism and proactive health choices, highlighting the immediate impact that lifestyle decisions can have on the microbiome and overall health.