How to Optimize Your Brain-Body Function & Health | Huberman Lab Podcast #30

Summary

• Interoception is the sense of one's internal landscape, including things like heartbeat, breathing, and gut feeling
• High fiber diets may reduce diversity in the gut microbiome and lead to less inflammation, while fermented foods (1-2 servings per day) may increase anti-inflammatory markers and improve gut microbiome diversity
• The sense of self, including interoception, can affect bodily and brain health, performance in life, and healing rates
• The brain and body communicate through various pathways, including the nervous system, hormones, and the immune system
• The gut microbiome is important for maintaining health and can be influenced by diet, sleep, stress, and exercise
• The vagus nerve, which runs from the brainstem to the abdomen, is important for communication between the brain and body and can be stimulated through activities such as cold water exposure, singing, and massages
• The sympathetic and parasympathetic nervous systems, also known as the "fight or flight" and "rest and digest" systems, respectively, can be balanced through activities such as meditation, deep breathing, and cold water exposure
• Chronic inflammation can have negative effects on the body and can be reduced through diet, sleep, stress management, and exercise
• The topic of sense of self, or interoception, is important for health and performance
• Interoception is important for how we feel and what we are capable of doing
• Taking care of interoception is important for sleep, short and long-term health, performance, mental focus, mood, stress regulation, and healing
• Sense of self involves two key features and can be improved by understanding what modulates or changes these features
• Nutrition, exercise, and supplementation can improve sense of self and lead to feeling better and being more capable
• The brain is the command center of the body, but does not have its own sensation or movement
• The organs in the body communicate mechanical and chemical information to the brain to help it function properly
• Proper regulation of the mechanical and chemical environment of the body can improve brain function
• The chemistry of the gut, spleen, lungs, and diaphragm can be changed to improve immune function and heal injuries
• The diaphragm is a muscle that helps with breathing and can be controlled to improve chemical and mechanical communication in the body
• Deep abdominal breathing can improve the function of the diaphragm and overall communication in the body
• The Vagus nerve plays a role in communication between the gut and the brain and can be stimulated through deep breathing and other techniques
• The brain sends a signal to the heart to speed up when you inhale, and to slow down when you exhale
• Inhales and exhales affect heart rate because of the mechanical changes in the diaphragm and lungs and the mechanical changes in the heart
• The relationship between the diaphragm, lungs, brain, and heart is autonomic and automatic
• Exhales slow the heart down because of a change in mechanical pressure between the diaphragm, lungs, and heart
• Mechanical changes in the viscera can change the way the brain works and the brain can change the way the viscera work
• Emphasizing exhales can help to calm the mind and body
• The piezo receptors are located in many tissues and inform the brain about pressure in those tissues
• The lungs have a particular type of piezo receptor called piezo two receptors, which send information to the brain about how full the lungs are
• The impulse to breathe is triggered by neurons that are activated when carbon dioxide levels in the bloodstream reach a certain threshold
• The relationship between the bloodstream and breath is that inhaled air and the oxygen molecules in it move from the lungs into the bloodstream, and exhaled air moves from the bloodstream into the air through the lungs
• The body has a number of mechanisms for regulating the concentration of oxygen and carbon dioxide in the blood, including the respiratory center in the brain and the aortic and carotid bodies
• The respiratory center in the brain receives input from the body's chemical and mechanical sensors and sends signals to the muscles responsible for breathing
• The aortic and carotid bodies are located in the major arteries and sense changes in blood oxygen levels, sending signals to the respiratory center in the brain to adjust breathing as needed
• The blood pH also affects breathing, with low pH (acidosis) causing faster and deeper breathing, and high pH (alkalosis) causing slower and shallower breathing
• Free diving involves modulating air intake and diaphragm and lung mechanics to alter the chemistry of the bloodstream and affect the brain
• This practice can lead to a state of alertness and calm
• Wim Hof and Tumo breathing are examples of this practice
• Understanding the mechanisms behind breathing and heart rate can allow for the creation of personalized breathwork practices
• Changing the way you breathe can alter the chemistry of the body and affect the immune system and inflammation
• Baroreceptors play a role in the reflex that occurs when the body senses a change in blood pressure.
• The Vagus nerve plays a role in heart rate and the Hering-Breuer reflex, which helps regulate breathing.
• The gut can control the brain's desire to eat or not eat through pressure receptors and sphincters
• Overconsumption of food or fluid can lead to dangerous expansion of the gut
• The empty or full state of the gut can affect the brain's desire to eat through the stimulation of neurons
• The gut and brain can communicate through mechanically-induced signals
• Protocol 6 involves fasting to enhance communication between the gut and brain
• The gut microbiome can also influence communication between the gut and brain
• The gut and brain can communicate through the Vagus nerve, which can be influenced through certain practices such as cold exposure, meditation, and deep breathing.
• The Liberles Lab at Harvard Medical School studies gut-brain communication and other aspects of viscera-brain communication
• They discovered a category of neurons called GLP1R neurons that are located near the neck and send branches to the intestines and stomach to sense how stretched out the intestines are and how fast things are moving through the intestines
• These neurons also send a branch to the brain that can trigger the desire to eat more or stop eating
• Another category of neurons called GPR65 neurons send connections to the gut and intestines to sense the presence of certain nutrients and send this information to the brain
• The GPR65 neurons are activated by omega-3 fatty acids found in certain animal and plant substances and amino acids
• Neurons that line the gut in collaboration with the GPR65 neurons also respond to glucose and also send this information to the brain
• It is possible to understand and modulate hunger by leveraging the activity of these neurons
• The process of digestion involves cinching off sphincters in the gut, tumbling food with smooth muscles, and breaking down food with enzymes
• Neurons in the gut and intestines communicate the presence and processing of food to the brain through various means such as electrical activity, neurotransmitters, and hormones
• The gut microbiome also plays a role in gut-brain communication and can influence various aspects of health and behavior through mechanisms such as the production of neurotransmitters and modulation of immune function
• The pH of the gut should be more acidic than other tissues in the body to function properly
• Antacids are used to treat acid reflux, but only address the symptom and not the cause
• Maintaining proper gut chemistry (acidicity and alkalinity) is important for brain and body health
• The microbiome in mucosal tissues, including the nose and gut, can be affected by the acidity/alkalinity of the tissue
• Probiotics and prebiotics can improve the gut microbiome and overall health
• Acidity in the gut can be increased through the use of hydrochloric acid supplement HCL
• Gastric juices can modulate brain state
• The gut microbiome can affect autoimmune function and other aspects of brain and body health
• A study compared the impact of a high fiber diet and a diet with fermented foods on the gut microbiome and markers of inflammation and immune function
• The fermented food diet showed better results than the high fiber diet, with some people experiencing negative effects from the high fiber diet
• People on the high fiber diet had increased enzymes that aided in digestion of carbohydrates
• Eating history and the types of foods a person eats may determine how well they can utilize and crave certain types of food
• Fermented foods may have a wide range of health benefits beyond just the gut microbiome
• Leaky gut can be prevented by consuming fermented foods and supplementing with glutamine
• Some people recommend treating food allergies, mood, and autoimmune issues through the ingestion of hydrochloric acid (HCL) tablets, combined with the enzyme pepsin, but this should be done with caution and after consulting with a healthcare provider
• Consuming high levels of probiotics or prebiotics can cause brain fog
• Prebiotics may have a positive effect on mental health and cognition
• The gut microbiome can affect the immune system, inflammation, and the brain through the gut-brain axis
• The gut microbiome can be influenced by diet, stress, and antibiotics
• Dysbiosis (an imbalance in the gut microbiome) can contribute to mental health issues such as anxiety and depression
• Consuming a varied and plant-based diet can promote a healthy gut microbiome
• Exercise can also promote a healthy gut microbiome
• The blood brain barrier (BBB) prevents certain molecules from crossing into the brain to protect it.
• The BBB is not always uniform and there are small areas where chemicals can cross into the brain.
• The area postrema in the brainstem is responsible for detecting the chemistry of the bloodstream and triggering reflexes in the abdominal wall, such as vomiting, if the chemistry is off.
• The neurons in the area postrema can also be affected by thoughts, beliefs, and memories.
• Vomiting can be triggered by the sight or thought of vomit, or by negative experiences with vomit.
• Drinking too much alcohol can lead to a condition called "alcohol poisoning," which can cause the BBB to become leaky and allow toxins to cross into the brain.
• Leaky gut can also cause the BBB to become leaky, leading to inflammation in the brain and potentially contributing to conditions such as depression and anxiety.
• Fever is an increase in body temperature triggered by the brain in response to toxins, bacteria, and viruses in the bloodstream
• Fever is a mechanism to "cook" and eliminate the cause of the bad things in the body
• The fever mechanism is similar to the mechanism for vomiting, which involves neurons that can sense the chemistry of the cerebral spinal fluid and therefore the chemistry of the body
• Fever and vomiting are both adaptive mechanisms to protect the body
• Interoception is the ability to sense what is happening inside the body and to understand the internal state of the body
• Interoception involves both mechanical and chemical information accessing the brain
• The fever is an adaptive mechanism in which pyrogens, substances that cause fever, are unable to survive at high temperatures
• The organum vasculosum of the lateral terminalis (OVLT) senses chemistry to control the fever
• The vagus nerve is involved in communication between the brain and body and in changing the function of different organs
• Stress can disrupt communication between the gut and brain and alter the chemistry of the gut, leading to poor digestion and other negative effects
• The vagus nerve is responsible for emotion and pools information from the gut, heart, and breathing to send to the brain, which then affects the perception of emotion
• Interoception, or the sense of the internal state of the body, is important for understanding and expressing emotions
• The insular cortex is involved in interoception and integrating information from different senses to create a cohesive perception of the body's internal state
• The insular cortex is also involved in decision making and moral reasoning