Dr. Diego Bohórquez: The Science of Your Gut Sense & the Gut-Brain Axis

Dr. Diego Bohórquez (00:00:00)

• Dr. Diego Bohórquez is a professor of medicine and neurobiology at Duke University.
• He is a pioneer and leader in the field of gut sensing or the gut-brain axis.
• His research focuses on the actual sensing that occurs within the gut, rather than the microbiome.
• The gut contains receptors that respond to specific components of food, including amino acids, fats, sugars, temperature, acidity, and other micronutrients.
• This information is communicated to the brain below our conscious detection, influencing our thinking, emotions, and behavior.
• Gut sensing is the ability to perceive and respond to the contents of the gut.
• It involves the activation of specific neurons and neural circuits in the gut.
• The brain responds to gut sensing by altering our thoughts, feelings, and behaviors.
• Gut sensing is influenced by the types and qualities of food we ingest.
• Different foods and food combinations can impact how we feel, what we crave, and what we avoid.
• Gut sensing plays a role in our overall sense of well-being, safety, excitement, depression, sadness, anger, and happiness.
• Dr. Bohórquez's research has uncovered the extraordinary relationship between nutrition and neuroscience.

Sponsors: Joovv, LMNT & Helix Sleep; YouTube, Spotify & Apple Subscribe (00:02:37)

• The podcast is separate from the speaker's teaching and research roles at Stanford.
• The speaker aims to provide free science-related information to the public.
• Today's sponsors are Joovv (red light therapy devices), LMNT (electrolyte drink), and Helix Sleep (mattresses and pillows).
• The gut-brain axis is a bidirectional communication pathway between the gastrointestinal tract and the central nervous system.
• The gut microbiome, composed of trillions of microorganisms, plays a crucial role in this communication.
• Gut dysbiosis, an imbalance in the gut microbiome, has been linked to various health conditions, including gastrointestinal disorders, metabolic diseases, and mental health issues.
• The gut-brain axis influences various aspects of brain function, including mood, cognition, and behavior.
• The vagus nerve, a major component of the gut-brain axis, transmits signals between the gut and the brain, allowing for communication in both directions.
• Gut hormones, such as ghrelin and leptin, also play a role in regulating appetite, metabolism, and mood.
• The gut-brain axis is involved in stress response, with chronic stress affecting the gut microbiome and gut function.
• Prebiotics and probiotics can help improve gut health and positively impact the gut-brain axis.
• A healthy diet, regular exercise, and stress management are essential for maintaining a healthy gut-brain axis.

Gut-Brain Axis (00:06:49)

• The gut-brain axis is a term used to describe the communication between the gut and the brain.
• Traditionally, this communication was thought to occur solely through hormones released by the gut and entering the bloodstream.
• Recent research has shown that there are also sensory cells in the gut that can detect the outside world and quickly communicate that information to the brain.
• The gut is the only organ that passes through our body but is still exposed to the outside world.
• There are different modes of sensing what's coming through the gut and signaling to the brain and other organs what's going on in the outside world.
• When we swallow something, we have to trust our gut because there's not much we can consciously do to expel something poisonous or toxic.
• The gut has to make the distinction between what is safe and what is not and then accommodate things for absorption or let them pass through digestion.

Gut Sensing, Hormones (00:11:35)

• Gut sensing involves epithelial cells that line the digestive tract and interface with the body's interior.
• Enteroendocrine cells, found in the epithelial layer, release hormones and neuromodulators.
• Enteroendocrine cells were initially thought to communicate with the nervous system through diffusion of neuromodulators.
• In 2015, it was discovered that some enteroendocrine cells directly contact the nervous system, providing a new dimension to gut-brain communication.
• Synapses are predominant in the brain, but neuromodulation from endocrine functions also occurs.
• The lack of proper tools hindered the study of synaptic contacts between enteroendocrine cells and the nervous system.
• Advancements in cell tagging techniques, such as green fluorescence protein, revolutionized biology and enabled detailed study of enteroendocrine cells.

Green Fluorescent Protein; Neuropod Cells & Environment Sensing (00:15:26)

• Cells in the gut can sense food and release hormones that influence the brain and other organs, forming a direct line of communication known as the gut-brain axis.
• Scientists have developed tools like green fluorescent protein and optogenetics to study the brain and neural circuitry.
• In 2009, scientists discovered that certain factors can trigger stem cells in the intestinal epithelium to form mini-guts in a dish.
• Neuropods are specialized cells found in various epithelial layers, including the gut, skin, inner ears, and taste buds, that respond to environmental changes and generate chemo-electrical signals.
• Neuropods play a crucial role in transmitting information from the external environment to the brain, influencing our thoughts, feelings, and behaviors.
• Consuming foods that disrupt the gut-brain axis, such as certain types of lettuce, can negatively impact our health.

Brain & Gut Connection, Experimental Tools & Rabies Virus (00:26:57)

• Dr. Diego Bohórquez discovered a direct gut-to-brain pathway, allowing the gut to influence feelings and decision-making.
• Gut cells are dynamic, constantly moving, and sensing chemicals in the gut environment.
• These gut cells extend processes to the brain, connecting to the nervous system and transmitting information about the gut.
• This pathway was confirmed in mice using a modified rabies virus, showing a direct connection from the gut to the brain stem.
• Interoception, the ability to sense internal bodily states, can be enhanced through practices like meditation, but excessive awareness can sometimes be disruptive.
• The modified rabies virus, used for research purposes, only jumps one synaptic connection and stops, allowing for targeted tracing of neural circuits.

Dr. Diego Bohórquez: The Science of Your Gut Sense & the Gut-Brain Axis (00:00:00)

• Dr. Diego Bohórquez is a neuroscientist who studies the gut-brain axis.
• The gut-brain axis is a bidirectional communication pathway between the central nervous system and the gastrointestinal tract.
• The gut microbiome is a community of trillions of bacteria, viruses, and other microorganisms that live in the human gut.
• The gut microbiome plays a vital role in human health by helping to digest food, produce vitamins, and regulate the immune system.
• Dysbiosis, an imbalance in the gut microbiome, has been linked to a number of health problems, including obesity, diabetes, and inflammatory bowel disease.
• The vagus nerve is a long nerve that connects the brain to the gut.
• The vagus nerve plays a key role in the gut-brain axis by transmitting signals between the gut and the brain.
• Stimulation of the vagus nerve has been shown to have a number of therapeutic benefits, including reducing inflammation, improving digestion, and relieving stress.
• The enteric nervous system is a network of nerves that controls the gut.
• The enteric nervous system is often referred to as the "second brain" because it can function independently of the central nervous system.
• The enteric nervous system plays a key role in digestion, absorption, and elimination.
• The gut-brain axis plays a role in mental health by influencing the production of neurotransmitters, such as serotonin and dopamine.
• Dysbiosis has been linked to a number of mental health problems, including depression, anxiety, and schizophrenia.
• Probiotics, live microorganisms that have health benefits when consumed, have been shown to improve mental health by restoring balance to the gut microbiome.
• The gut-brain axis is a complex system that plays a vital role in human health.
• Dysbiosis can have a number of negative consequences for physical and mental health.
• Probiotics and other interventions that support the gut microbiome can help to improve overall health and well-being.

Neuropod Cells & Nutrient Sensing (00:37:00)

• Neuroplastic cells in the gut lining detect chemicals and physical changes resulting from food breakdown and send signals to the brain.
• These enteroendocrine cells have multiple receptors for various nutrients, including sugars, fats, proteins, and fibers, and their location along the digestive tract determines the specific nutrients they detect.
• Glucose activates the sweet taste receptor tas1R3 and is absorbed by sodium-glucose transporters, depolarizing the cell and causing the release of transmitters that signal the vagus nerve about the presence of sugar.
• The metabolism of glucose also causes the release of a neuropeptide, giving the full experience of consuming sugar.
• The gut integrates information about the ingested molecule's chemistry, taste, and absorption to make changes in the gut and signal elsewhere in the body.

Gastric Bypass Surgery, Cravings & Food Choice (00:43:55)

• The gut evaluates various aspects of food, including macronutrients, micronutrients, temperature, and amino acid quality.
• Gastric bypass surgery reduces the stomach size and reroutes the connection between the stomach and intestine, leading to rapid physiological changes.
• Changes after gastric bypass surgery suggest the gut's role beyond nutrient absorption, influencing body weight, diabetes, and food preferences.
• The gut has sensory cells that detect nutrients and rapidly adapt their function to nutrient presence changes.
• Gastric bypass surgery can alter food cravings, possibly due to the removal of nutrient-sensing cells in the gut.
• Initially, gastroenterologists had limited knowledge about gastric bypass surgery's impact on food choices.
• Clinical reports in 2011 and subsequent studies confirmed that gastric bypass surgery changes food preferences and choices.

Optogenetics; Sugar Preference & Neuropod Cells (00:51:14)

• Optogenetics allows scientists to control specific cells using light.
• Researchers used optogenetics to study the role of gut cells in sugar preference behavior in animals.
• Animals prefer sugar water over artificial sweeteners, even without sweet taste receptors in their mouths.
• Sodium glucose transporters in the intestine may detect sugar and guide sugar preference behavior.
• Gut cells and brainstem neurons integrate information from the gut to guide sugar preference behavior.
• Humans crave sugar from an early age due to the body's energy needs.
• The gut-brain axis regulates food cravings and consumption.
• Sweet taste receptors in the gut sense sugar and signal the brain to seek more sugar, independent of conscious sweetness perception.
• Disrupting these gut receptors can impair the ability to distinguish between sweeteners and sugar.
• Excessive consumption of sugary foods can lead to a cycle of cravings and weight gain.

Gut-Brain Disorders, Irritable Bowel Syndrome (01:00:29)

• Experiments show that activating certain cells in the gut makes mice crave non-caloric sweeteners as if they were sugar.
• The gut has a basic sense that calculates the intensity and valence (pleasure or pain) of stimuli.
• Serotonin-releasing cells in the colon couple to nerve fibers of the spinal cord and drive visceral hypersensitivity, which is responsible for triggering the hypersensitivity of colonic nerve fibers.
• This could be the biological basis of irritable bowel syndrome and other chronic GI disorders.

Sponsor: InsideTracker (01:03:03)

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Gut & Behavior; Gastric Bypass, Cravings & Alcohol (01:04:04)

• Sensory cells along the digestive tract evaluate the chemical constituents of food.
• These cells emit hormonal signals to change appetite, well-being, and potentially emotions and behavior.
• Direct signals are also sent to the brain to influence thinking, emotions, and behavior.
• Gastric bypass surgery can rewire the gut, making it more sensitive to stimuli.
• This can lead to changes in food preferences and cravings, such as an increased likelihood of developing alcoholism.

GLP-1, Ozempic, Neuropod Cells (01:07:38)

• GLP-1 (glucagon-like peptide-1) is a potent stimulator of insulin release in the pancreas.
• GLP-1 levels increase after gastric bypass surgery.
• GLP-1 acts locally on nerve fibers, especially of the vagus nerve.
• GLP-1 is released by enteroendocrine cells in the digestive tract in response to macronutrients, primarily sugar.
• GLP-1 acts on specific receptors of the nerve terminals to trigger behaviors related to appetite reduction.
• GLP-1 also acts at the level of the brainstem to potentiate appetite reduction.
• GLP-1 interacts with neuropod cells, which release GLP-1 to transiently shut down hunger.
• GLP-1 may also interact with other cells through autocrine or paracrine signaling.

Food Preference & Gut-Brain Axis, Protein (01:11:46)

• The gut-brain axis influences food choices based on taste, macronutrient ratios, micronutrients, and physical volume.
• Highly processed foods lead to excess calorie intake compared to single or two-ingredient foods.
• The gut evaluates protein presence in meals and may stop eating or avoid foods lacking it, especially animal-based proteins.
• The gut-brain axis communicates between the digestive tract and the brain, influencing food cravings and satiety.
• Essential amino acids from animal proteins signal the brain to crave more of those foods until satisfaction is reached.
• In the absence of sufficient protein, the body may avoid that particular food unless it contains high amounts of dietary fiber.
• Gut microorganisms can synthesize essential amino acids when provided with highly digestible fiber, compensating for the lack of protein from animal sources.
• Consuming a small amount of protein can lead to increased cravings as the body tries to compensate for the lack of essential amino acids.
• Limiting meat intake can result in increased hunger, suggesting it's better to either indulge in meat or avoid it altogether rather than consuming small amounts.
• Mosquitoes require protein to lay eggs and cannot reproduce without it.

Protein & Sugar, Agriculture & ‘Three Sisters’ (01:21:35)

• Gut sensing cells (neurop pods) are sensitive to amino acid content in foods.
• Protein is the most satiating macronutrient and essential for brain and body functions.
• Eating sufficient amounts of protein can reduce sugar cravings.
• In agriculture, there's an instinct to plant complementary plants like the "three sisters" (pumpkins, corn, and beans) to obtain a balanced diet of fiber, sugar, and amino acids.
• Humans have developed an instinct to cultivate plants in a way that provides nutritional balance when combined on a plate.

Childhood, Military School; Academics, Nutrition & Nervous System (01:25:16)

• Dr. Diego Bohórquez grew up in a rural town in the Amazonia of Ecuador, where electricity and modern conveniences were scarce.
• He attended a prestigious military school in Ecuador and was selected for special training due to his academic performance.
• Dr. Bohórquez studied agriculture at Zamorano University in Honduras, where he learned about nutrition and the importance of pursuing a Ph.D.
• During his Ph.D. in nutrition at North Carolina State University, he became fascinated with the nervous system and its role in the body's functions.
• Dr. Bohórquez applied his knowledge of the nervous system to his work on the gut, leading to his research on the gut-brain axis.

Plant Wisdom, Agriculture, Indigenous People (01:36:15)

• Plants have been on Earth for millions of years longer than animals and have had more time to experience and adapt to their environment.
• Plants may possess wisdom gained from their extensive experience, which we can potentially tap into for valuable information about the environment and climate.
• Indigenous people who have lived in the jungle for generations have developed a heightened sensory perception and understanding of their surroundings, allowing them to navigate and interact with the environment effectively.
• Plants have been integral to indigenous communities, serving various purposes such as food, medicine, textiles, and materials for tools and shelter.

Evolution of Food Choices; Learning from Plants (01:41:48)

• The gut-brain axis plays a crucial role in discerning the nutritional value and safety of various plants, nuts, and berries.
• The trial-and-error process of consuming different plant materials led to the development of neurop pod cells, which aid in decision-making regarding food choices.
• Despite extensive anthropological research on the interactions between native people and plants, there is a gap in biological understanding regarding how humans learned to identify safe and nutritious plants.
• Native people often describe learning from plants, suggesting a deeper understanding of plant properties beyond scientific classification systems.
• Native people use a rich classification system that considers factors like flavor, shape, location, and interactions over the year.
• Native people interact with plants with respect and consider them sacred.

Plant-Based Medicines; Amazonia, Guayusa Ritual & Chonta Palm (01:48:15)

• Plants have been a traditional source of medicine, with around 80% of current medicines derived from them.
• Plants like Guayusa, Mate, and Cha are consumed by some cultures to suppress appetite and provide energy, forming a "full meal" until 3 p.m.
• The combination of hydration, caffeine, and lipids in their diet helps stave off hunger.
• Morning rituals involving conversations about family, culture, and planning the day are common in many cultures.
• Fireside chats, where people reflect on the previous day and discuss social and work issues, have existed in many cultures, promoting building and repairing relationships within the community.

Yerba Mate, Chocolate, Guayusa (01:56:58)

• The speaker enjoys drinking guayusa and yerba mate, sometimes mixing the two.
• He appreciates the ability to continuously pour water over the leaves and experience different flavors as the concentration changes over time.
• The speaker acknowledges that while they are discussing precise neurons and sensing at the gut level, they are also taking a broader view of plants and their complex compositions.
• He mentions visiting a friend who produces some of the best chocolate in Ecuador, the origin of theobroma cacao.
• The speaker highlights the exceptional quality of dark chocolate, especially when it comes from a reliable source, and suggests trying it with guayusa for an energizing experience.
• He describes the combination of guayusa and chocolate as a smooth and enjoyable drink that can provide a significant energy boost, potentially explaining why certain groups consume guayusa early in the day.

Brain, Gut & Sensory Integration; Variability (02:00:22)

• The gut communicates with the brain through the vagus nerve and the nodose ganglion, influencing hunger, appetite, and reward systems in the brain.
• Sphincters control the movement of food through the digestive tract, affecting processing time.
• The gut-brain axis is a bidirectional pathway between the gastrointestinal tract and the central nervous system, involving the gut microbiome and neurotransmitters.
• The gut-brain axis influences digestion, metabolism, immune function, and mood regulation.
• Dysregulation of the gut-brain axis is linked to various health conditions, including irritable bowel syndrome, inflammatory bowel disease, obesity, and depression.
• Maintaining a healthy gut microbiome through diet, exercise, and stress management can positively impact overall health.

Electrical Patterns in Gut & Brain, “Hangry” (02:06:01)

• The gut generates electrical patterns that change depending on fasting, feeding, and circadian rhythms. These patterns are coordinated by interstitial cells of Cajal and may modulate the entire body's electricity, synchronizing with the brain's electrical activity.
• The gut-brain axis is a fascinating area of future research to understand how the body and brain's electrical waves synchronize.
• The gut and the brain are connected at an organ-to-organ level, allowing the brain to integrate the outside world and food into the entire system to maintain the organism.
• Our level of alertness is linked to our level of anticipation, and food anticipation impacts our levels of arousal.
• As diurnal species, our appetite is usually greater during the day than in the middle of the night due to different digestion rates and pathway shutdowns.

Gut Intuition, Food & Bonding; Subconscious & Superstition (02:12:43)

• The gut-brain axis, particularly the vagus nerve, facilitates communication between the gut and the brain, influencing psychological aspects and intuition.
• Gut feelings are shaped by subconscious experiences stored in the body, and different languages have phrases that describe these feelings, such as "frevo da barriga" in Portuguese and "presentimiento" in Spanish.
• Sharing similar food can synchronize intuition and enhance connection and bonding among people.
• The chemical components of food and the act of sharing meals contribute to bonding and decision-making, particularly in romantic relationships and business settings.
• Walter Cannon, a renowned physiologist, explored the concept of psychosomatic death in certain African tribes, suggesting that fear and superstition could trigger hyperactivation of the vagus nerve and the peripheral nervous system, leading to a learned association between events and physiological changes.

Vagus Nerve & Learning, Humming (02:22:00)

• Vagus nerve activation can have both calming and arousing effects.
• Vagus nerve stimulation is used to treat depression and induce alertness.
• Vagus nerve activity can be influenced by learning and practices such as long exhale breathing and humming.
• Humming is linked to vasodilation and a calming effect.
• Certain music and sounds can activate the vagus nerve and influence arousal levels.
• Macroscopic signals like light and sound play a significant role in our feelings of well-being and arousal.

Digestive System & Memory; Body Sensing (02:26:46)

• The gut-brain axis is a complex system involving communication between the digestive system and the brain.
• The gut plays a crucial role in memory and emotions, closely linked to taste and smell.
• The gut communicates with the brain through electrical signals, influencing feelings and impressions.
• Modern humans are exploring ways to incorporate the ancient gut-brain axis into decision-making, acknowledging its sophistication.
• The body's capabilities are highlighted when enjoying a meal while engaging in meaningful conversations, showcasing its intricate functions.

Listening to the Body, Meditation (02:32:51)

• Paying attention to gut feelings and body signals is crucial for overall well-being and can help make better decisions in various aspects of life.
• Ignoring the body's signals can lead to health problems, as exemplified by the speaker's personal experience of a foot injury.
• The gut microbiome is vital for health, and simple actions like increasing fiber and fermented food intake can positively impact it.
• Dr. Diego Bohórquez, a pioneer in understanding the gut-brain axis, expresses gratitude for the opportunity to share his work and acknowledges the contributions of his team, mentors, and institutions, including Duke University.
• Dr. Bohórquez emphasizes the importance of public dialogue to enhance our understanding of the world and appreciates the platform provided to share research findings.

Dr. Diego Bohórquez: The Science of Your Gut Sense & the Gut-Brain Axis (00:00:00)

• Dr. Diego Bohórquez is a neuroscientist and the host of the podcast "The Gastronauts".
• The gut-brain axis is a bidirectional communication pathway between the central nervous system and the enteric nervous system.
• The gut microbiome, which consists of trillions of bacteria, viruses, and other microorganisms, plays a crucial role in the gut-brain axis.
• The gut microbiome produces neurotransmitters, such as serotonin and dopamine, which can affect mood and behavior.
• The gut microbiome can also influence the immune system and inflammation, which are linked to various neurological disorders.
• Dysbiosis, an imbalance in the gut microbiome, has been associated with conditions such as obesity, diabetes, and depression.
• The vagus nerve is a major component of the gut-brain axis.
• The vagus nerve transmits signals between the gut and the brain, allowing for communication between the two organs.
• The vagus nerve also regulates digestion, heart rate, and immune function.
• The gut-brain axis plays a crucial role in overall health and well-being.
• Dysbiosis and other disruptions to the gut-brain axis have been linked to various health conditions, including:
  • Obesity
  • Diabetes
  • Depression
  • Anxiety
  • Inflammatory bowel disease
  • Autism spectrum disorder
• Maintaining a healthy gut microbiome and supporting the gut-brain axis can help prevent and manage these conditions.
• Eat a healthy diet, rich in fiber, fruits, vegetables, and whole grains.
• Avoid processed foods, sugary drinks, and excessive amounts of alcohol.
• Get regular exercise.
• Manage stress through techniques such as meditation, yoga, and deep breathing.
• Get enough sleep.
• Consider taking probiotics or prebiotics to support the gut microbiome.