At some point in your life, you’ve likely been told to “trust your gut” when making a decision or experienced a “gut reaction” to external stimuli. Medical research indicates that these gut idioms might just be right about the role of the gut! It turns out that the gut microbiome communicates with the brain and can potentially influence our behavior. Researchers have named this link the gut-brain axis and it provides a robust communication network between the gastrointestinal tract and central nervous system. At its core is the enteric nervous system which has more than 5 times the number of neurons in our brains and trillions of microorganisms. This system has been dubbed the “second brain” or the “gut-brain” for its influence on our overall physical and mental health.

Our guest today is neuroscientist John Cryan, PhD. Professor Cryan investigates how the gut microbiome affects the mammalian brain. He is Chair of the Department of Anatomy and Neuroscience and Principal Investigator in the Alimentary Pharmabiotic Center at University College of Cork (Ireland). Dr. Cryan’s research has demonstrated the bi-directional relationship between our gut and emotional and mental wellbeing.

In this episode Dr. Weil, Dr. Maizes, and Professor Cryan discuss the role the vagus nerve plays in regulating homeostasis, how chemicals released in the gut send signals to the brain, how maternal bacteria influence our early development, the link between sleep and gut health, and how diet can influence this complex system.