Podcasts > The School of Greatness > How To HEAL Your Gut Microbiome for Better Mood, Weight Loss & Disease Prevention

How To HEAL Your Gut Microbiome for Better Mood, Weight Loss & Disease Prevention

By Lewis Howes

In this episode of The School of Greatness, Lewis Howes and experts William Li and Will Bulsiewicz discuss the connection between gut health and mental well-being. They explore research showing how an unhealthy gut microbiome can lead to inflammation, affecting cognitive function and mood disorders, while explaining how exercise and dietary changes can improve gut health within 24 hours.

The conversation examines specific ways to maintain a healthy gut microbiome, including the benefits of consuming diverse plant-based foods and the importance of fiber intake. The experts also address how modern lifestyle factors—such as ultra-processed foods, alcohol, smoking, and cooking fumes—can disrupt gut health and potentially lead to inflammation and DNA damage.

Listen to the original

How To HEAL Your Gut Microbiome for Better Mood, Weight Loss & Disease Prevention

This is a preview of the Shortform summary of the Apr 25, 2025 episode of the The School of Greatness

Sign up for Shortform to access the whole episode summary along with additional materials like counterarguments and context.

How To HEAL Your Gut Microbiome for Better Mood, Weight Loss & Disease Prevention

1-Page Summary

Gut-brain Connection: Impact on Mental Health

In a fascinating discussion, Lewis Howes, William Li, and Will Bulsiewicz explore the crucial connection between gut health and mental well-being, revealing how our microbiome influences our mental state.

The Gut-Brain Connection and Mental Health

Will Bulsiewicz explains that inflammation from an unhealthy gut microbiome can significantly impact cognitive function and mood disorders. He notes that even exercise alone can shift the microbiome toward producing anti-inflammatory molecules, potentially improving mood. Research has shown that bacterial inflammation can lead to lowered mood, decreased motivation, and social withdrawal.

William Li describes the gut as an "undiscovered country," emphasizing its integral role in both mental and physical wellness. The experts highlight that people with major depression often show signs of a weakened gut microbiome, suggesting that improving gut health could help alleviate mental health symptoms.

Dietary Approaches to Gut Health

According to Bulsiewicz and Li, dietary diversity, particularly from plant-based foods, is crucial for maintaining a healthy gut microbiome. The American Gut Project recommends consuming at least 30 different types of plant foods weekly for optimal gut health. Li notes that positive changes can begin within just 24 hours of eating whole, fresh foods like kiwis.

Bulsiewicz emphasizes the importance of fiber from plant foods, explaining that it promotes the release of essential gut hormones like GLP1, which helps regulate appetite and blood sugar levels.

The Impact of Modern Diet and Lifestyle

Shawn Stevenson discusses how ultra-processed foods, containing inflammatory sugars, preservatives, and unhealthy fats, can severely disrupt the gut microbiome. William Li compares this to putting poor-quality fuel in a car, while Bulsiewicz adds that these foods promote sugar-loving, inflammation-creating bacteria.

The experts also highlight how lifestyle factors, including alcohol consumption, smoking, vaping, and even cooking fumes, can compromise gut health. Stevenson points to research showing that vegetable oil fumes during cooking may have DNA-damaging effects, while Li emphasizes the particular risk for restaurant line cooks who face constant exposure to these fumes.

1-Page Summary

Additional Materials

Counterarguments

  • While there is evidence suggesting a connection between gut health and mental health, the relationship is complex and not fully understood; other factors such as genetics, environment, and personal history also play significant roles in mental health.
  • The recommendation to consume at least 30 different types of plant foods weekly may not be practical or affordable for everyone, and there is no one-size-fits-all dietary approach to gut health.
  • Positive changes in gut health from dietary adjustments may not occur as quickly for everyone, and individual responses to dietary changes can vary widely.
  • The role of fiber in promoting gut hormones like GLP1 is well-documented, but other nutrients and dietary components also contribute to gut health and should not be overlooked.
  • The impact of ultra-processed foods on gut health is a concern, but moderation and a balanced diet can be a more realistic approach for many people rather than complete avoidance.
  • Lifestyle factors such as alcohol consumption and smoking have well-established health risks, but the impact on gut health specifically may not be as direct or significant as other health consequences.
  • The assertion that vegetable oil fumes during cooking have DNA-damaging effects may require more context, as the risk could be dependent on the type of oil used, the temperature, and the duration of exposure.
  • The risks faced by restaurant line cooks from cooking fumes are a valid concern, but there may be mitigating factors such as ventilation systems and cooking techniques that can reduce exposure.

Actionables

  • You can track your plant variety intake with a simple color-coding system in your meal planner to ensure dietary diversity. Assign a different color to each plant category (e.g., green for leafy vegetables, red for fruits, yellow for grains) and aim to include as many colors as possible in your weekly diet. This visual approach makes it easier to spot which types of plants you might be neglecting and encourages you to incorporate a wider variety into your meals.
  • Create a "gut-friendly" recipe swap club with friends or family to exchange meals that are rich in diverse plant foods and low in processed ingredients. Each member could contribute one recipe per week, focusing on whole foods and fiber-rich ingredients. This not only expands your culinary repertoire but also fosters a supportive community focused on improving gut health together.
  • Optimize your kitchen environment by investing in an air purifier with a HEPA filter to reduce exposure to harmful cooking fumes, especially if you cook with oils regularly. Additionally, practice cooking methods that produce fewer fumes, such as steaming or baking, and ensure good ventilation by using an exhaust fan or opening windows when cooking to minimize the inhalation of potentially damaging particles.

Get access to the context and additional materials

So you can understand the full picture and form your own opinion.
Get access for free
How To HEAL Your Gut Microbiome for Better Mood, Weight Loss & Disease Prevention

Gut-brain Connection: Impact on Mental Health

Lewis Howes, William Li, and Will Bulsiewicz explore the critical link between gut health and mental well-being, suggesting that nurturing our microbiome could improve mental health.

Gut Microbiome Linked To Brain Health and Mood Disorders

Unhealthy Gut Microbiome's Inflammation Affects Cognitive and Mental Health

William Li refers to the gut as an "undiscovered country," playing an integral role in both mental and physical wellness. Will Bulsiewicz posits that simple dietary changes can impact the microbiome, subsequently affecting brain health and mood disorders. They both recognize that with an overconsumption of ultra-processed foods, one creates an inflammatory microbiome. This inflammation is a fundamental aspect of various cognitive disorders and mood issues such as depression and anxiety.

Bulsiewicz highlights that even without altering diet, exercise can induce a shift in the microbiome towards anti-inflammatory molecules. Since depression has an inflammatory component, the microbiome shift due to exercise could potentially enhance mood.

Research involving the injection of lipopolysaccharide (produced by bacteria like E. coli) into human participants resulted in increased inflammation, lowered mood and motivation, and social withdrawal. These findings imply that inflammation connected to gut bacteria can detrimentally affect cognitive and mental health. Bulsiewicz elucidates that increased inflammation might cause the body to conserve energy to combat infection, contributing to cognitive downtrends.

Improving Gut Health May Alleviate Mental Health Symptoms

Diverse Gut Microbiome Supports Neurotran ...

Here’s what you’ll find in our full summary

Registered users get access to the Full Podcast Summary and Additional Materials. It’s easy and free!
Start your free trial today

Gut-brain Connection: Impact on Mental Health

Additional Materials

Clarifications

  • Lipopolysaccharide (LPS) is a molecule found in the outer membrane of certain bacteria. Injecting LPS into human participants in research studies can induce an inflammatory response in the body. This inflammation can lead to symptoms like lowered mood, decreased motivation, and social withdrawal, highlighting the potential impact of gut bacteria-related inflammation on cognitive and mental health.
  • Dysbiosis is an imbalance in the gut microbiome where there is an abnormal distribution of bacteria. This imbalance can lead to various health issues, including mental health disorders. In the context of mental health, dysbiosis has been associated with conditions like depression and anxiety. Restoring a healthy balance in the gut microbiome through dietary changes or probiotics may help alleviate symptoms of mental health disorders linked to dysbiosis.
  • Leaky gut, also known as increased intestinal permeability, occurs when the lining of the intestines becomes more porous, ...

Counterarguments

  • While there is evidence suggesting a link between gut health and mental well-being, the relationship is complex and not fully understood; other factors such as genetics, environment, and lifestyle also play significant roles in mental health.
  • The impact of dietary changes on the microbiome and mental health can vary greatly between individuals, and what works for one person may not work for another due to individual differences in metabolism, microbiome composition, and other factors.
  • The causality between an unhealthy gut microbiome and mood disorders is not definitively established; it is unclear whether an unhealthy microbiome contributes to mood disorders or if mood disorders lead to changes in the microbiome.
  • The idea that exercise can shift the microbiome towards anti-inflammatory molecules is intriguing, but more research is needed to understand the mechanisms and to establish exercise as a reliable intervention for improving gut health and mental well-being.
  • The injection of lipopolysaccharide as a model for studying inflammation's effect on mood and cognition may not fully replicate the complex interactions that occur naturally within the human body.
  • The concept of "leaky gut" is controversial and not universally accepted in the medical community; more research is needed to clarify its role in chronic inflammation and its connection to mental health disorders.
  • While a diverse gut microbiome m ...

Get access to the context and additional materials

So you can understand the full picture and form your own opinion.
Get access for free
How To HEAL Your Gut Microbiome for Better Mood, Weight Loss & Disease Prevention

Dietary Diversity and Plant-Based Foods for a Healthy Gut Microbiome

Experts stress the importance of dietary diversity, particularly in plant-based foods, to nourish the gut microbiome and promote overall health.

30 Diverse Weekly Plant Foods Nourish Gut Microbiome

William Li and Will Bulsiewicz advocate for a varied plant-based diet as the cornerstone of gut health.

Plant Foods Nourish Gut Bacteria, Promoting a Thriving Microbiome

The conversation suggests that a healthy gut microbiome is likely tied to the consumption of whole, unprocessed foods instead of items like "hot fries" or "Dr. Pepper." By opting for a plant-based diet that prioritizes whole foods, individuals may boost their gut health. This means choosing fresh food items and cooking them oneself, thereby flooding the body with diverse nutrients from Mother Nature and catalyzing gut healing.

Bulsiewicz underscores the importance of dietary diversity, particularly the array of different plants consumed. He points out that the monoculture of staple crops like wheat, corn, and soy, which constitutes 75% of supermarket calories predominantly in ultra-processed forms, is not conducive to gut health. The American Gut Project recommends at least 30 different types of plant foods per week as the number one predictor for a healthy gut microbiome. By including a wide range of plants – fruits, vegetables, whole grains, seeds, nuts, legumes, and mushrooms – different microbial families in the gut get fed, preventing certain bacteria from going "hungry."

Plant Fiber Fuels Beneficial Gut Bacteria Growth

Plant-Focused, Fiber-Rich Diet Boosts Gut Hormones For Appetite and Metabolism Regulation

Consuming whole fresh foods, for instance, kiwis, spurs the growth of healthy gut bacteria within just 24 hours, according to William Li, and other beneficial bacteria multiply within four days. Bulsiewicz underlines that fiber is a crucial part of our diet, and most Americans ...

Here’s what you’ll find in our full summary

Registered users get access to the Full Podcast Summary and Additional Materials. It’s easy and free!
Start your free trial today

Dietary Diversity and Plant-Based Foods for a Healthy Gut Microbiome

Additional Materials

Counterarguments

  • While dietary diversity is important, individual tolerance to certain plant foods can vary, and some people may experience adverse reactions to high-fiber diets or specific plant compounds.
  • The recommendation of 30 different types of plant foods per week may not be practical or affordable for everyone, and there is no one-size-fits-all dietary pattern that guarantees a healthy gut microbiome.
  • Some studies suggest that animal products can also contribute beneficial nutrients that support gut health, such as vitamin B12, iron, and omega-3 fatty acids, which are less abundant or bioavailable in plant-based foods.
  • The role of fermented foods, which are not exclusively plant-based, in promoting a healthy gut microbiome is not addressed, despite evidence suggesting they can be beneficial.
  • The emphasis on whole, unprocessed foods may overlook the fact that some processed foods can be part of a healthy diet, such as fortified plant milks or whole-grain bread.
  • The text does not consider the potential environmental impact of increasing demand for diverse plant foods, which could lead to issues such as over-farming and loss of biodiversity if not managed sustainably.
  • The claim that dietary fiber and polyphenols can alter the gut microbiome within a single day may be an oversimplification, as changes in the microbiome can be complex and influenced by many factors beyond ...

Actionables

  • You can create a "Plant Diversity Plate" for each meal, aiming to include at least five different plant-based ingredients. For example, breakfast could be a smoothie with spinach, banana, blueberries, flaxseed, and almond milk, while lunch could be a salad with mixed greens, chickpeas, quinoa, cherry tomatoes, and avocado.
  • Start a "30 Plants Challenge" where you track the variety of plant-based foods you eat weekly using a simple spreadsheet or a dedicated app. Set a goal to hit 30 different plants each week, and try new ones you haven't tried before, like dandelion greens, jicama, or starfruit, to keep things interesting and expand your gut microbiome diversity.
  • Organize a "Fiber-Focused Potluck" with friends or family wher ...

Get access to the context and additional materials

So you can understand the full picture and form your own opinion.
Get access for free
How To HEAL Your Gut Microbiome for Better Mood, Weight Loss & Disease Prevention

Impact of Ultra-Processed Foods and Unhealthy Lifestyle on Gut Health

Experts express concern about the increase in intake of ultra-processed foods and unhealthy lifestyle choices, emphasizing the long-term implications for gut health and overall wellness.

Ultra-Processed Foods Have Inflammatory, Gut-disrupting Sugars, Preservatives, and Unhealthy Fats

Eating Ultra-Processed Foods Leads to Gut Microbiome Imbalance

Shawn Stevenson highlighted the impact of ultra-processed foods like snacks and sugary drinks on health and suggests that the consumption of these items could lead to gut microbiome imbalance. He talks about the production of these foods which involves breaking down base ingredients like corn into substrates, such as corn syrup, and adding various additives that may disrupt the body's systems. Major concerns include the high content of unstable and pro-inflammatory polyunsaturated fatty acids (PUFAs) that have been linked to poor health outcomes. Stevenson emphasizes how the average American diet, specifically in adults and children, is overwhelmingly composed of ultra-processed foods. This is problematic due to the profound influence these foods have on hormones, potentially leading to an addictive quality and disrupting the balance of the gut microbiome.

William Li furthers this discussion by likening the body to a car and food as its fuel, indicating that ultra-processed foods may significantly compromise the gut microbiome. He warns that these types of foods are detrimental, comparing them to poor quality car fuel. Additionally, Li points out that the manufacturing processes for ultra-processed foods may even introduce microplastics, although their full effects are yet to be determined.

Will Bulsiewicz explains that a diet high in ultra-processed foods leads to microbial dysbiosis, as opposed to the diverse and healthy microbiome prompted by a varied diet. Ultra-processed foods promote sugar-loving, inflammation-creating bacteria, leading to an inflammatory microbiome and gut imbalance.

Lifestyle Habits Damaging Gut Microbiome

The implications of lifestyles on gut health were also highlighted. Unhealthy habits such as excessive alcohol consumption, smoking, sleep deprivation, and lack of exercise all negatively impact gut health. Li specifically brings up vaping and its harmful chemical introd ...

Here’s what you’ll find in our full summary

Registered users get access to the Full Podcast Summary and Additional Materials. It’s easy and free!
Start your free trial today

Impact of Ultra-Processed Foods and Unhealthy Lifestyle on Gut Health

Additional Materials

Clarifications

  • The gut microbiome imbalance caused by ultra-processed foods occurs when these foods disrupt the natural balance of bacteria in the gut. Ultra-processed foods typically lack fiber and essential nutrients, promoting the growth of harmful bacteria over beneficial ones. This imbalance can lead to inflammation in the gut and is associated with various health issues. Consuming a diet high in ultra-processed foods can alter the diversity and composition of the gut microbiome, impacting overall gut health.
  • Unstable and pro-inflammatory polyunsaturated fatty acids (PUFAs) are a type of fat found in certain foods. When consumed in excess, they can lead to inflammation in the body, which is linked to various health issues. These fats are considered unstable because they are prone to oxidation, which can further contribute to inflammation and damage in the body. Foods high in unstable and pro-inflammatory PUFAs include certain vegetable oils like soybean and corn oil.
  • Microplastics in ultra-processed foods are tiny plastic particles that can enter the food chain during processing and packaging. These particles can come from various sources like packaging materials or processing equipment. The full extent of the health implications of consuming microplastics in food is still being studied. Researchers are investigating how these particles may affect human health over the long term.
  • Lifestyle habits such as excessive alcohol consumption, smoking, poor sleep, and lack of exercise can negatively impact gut health by disrupting the balance of the gut microbiome. These habits can lead to inflammation, microbial imbalances, and overall poor gut health. Additionally, exposure to harmful chemicals from activities like vaping and inhaling cooking fumes can also affect the gut microbiome. Making healthier lifestyle choices can help maintain a diverse and healthy gut microbiome, promoting overall well-being.
  • Cooking fumes, particularly from sources like vegetable oils, can contain harmful compounds that, when inhaled, may have the potential to affect DNA and overall gut health. These fu ...

Counterarguments

  • Ultra-processed foods are not inherently unhealthy; it depends on the specific ingredients and the overall diet context.
  • Some preservatives and additives in ultra-processed foods have been approved by food safety authorities and are considered safe for consumption in regulated amounts.
  • Not all polyunsaturated fatty acids (PUFAs) are pro-inflammatory; omega-3 fatty acids, which are PUFAs, have anti-inflammatory properties.
  • The addictive quality of foods is a complex issue and may not be solely attributed to ultra-processed foods; psychological and social factors also play a significant role.
  • The presence of microplastics in ultra-processed foods is a concern, but the health implications are not fully understood and more research is needed.
  • Lifestyle habits such as moderate alcohol consumption and certain types of smoking (e.g., ceremonial or occasional use) may not have the same negative impact on gut health as excessive or habitual use.
  • The impact of cooking fumes on gut health may vary depending on the type of oil used, cooking temperature, and ventilation.
  • Some individuals may not experience significant negative effects from ultra-processed foods due to genetic factors or other aspects of their lifestyle.
  • The relationship between gut microbiome diversity and health is complex, and a causal link between ultra-p ...

Get access to the context and additional materials

So you can understand the full picture and form your own opinion.
Get access for free

Create Summaries for anything on the web

Download the Shortform Chrome extension for your browser

Shortform Extension CTA