b'CODING Update ComplianceLEGAL NUTRITIONCouncil THE GUT-BRAIN AXISBy Dr. Robert Silverman in Health and DiseaseANJC Leadership The matrix of the microbiome, the gut, and the braintheThe Role of Gut Bacteria in Brain HealthNUTRITIONRecent research confirms the idea that gut health and brain LEGAL EASE gut-brain axisis a new paradigm for understanding health.health are tightly linked. Metabolites excreted by gut bacteria When the matrix is functioning well, the body and mind function well. When the matrix is out of balance, physical health issuesare sensed by afferent nerve endings in the gut; their level is such as arthritis, diabetes, gut issues like IBS and IBD, foodreported to the brain via the vagus nerve. Bacterial metab-sensitivities, liver problems, inflammation, musculoskeletalolites include some substances that are very similar to brain disorders and autoimmune diseases can arise. Mental healthneurotransmitters such as dopamine. In other words, microbial suffers, and neurodegenerative disorders can develop. metabolites can interact with the brain and influence behavior REHAB Counciland feelings. The Role of the Vagus NerveThe vagus nerve (tenth cranial nerve) is the longest cranial nerve.The human gut contains over a thousand bacteria species. In Latin, the word vagus means wandering, an appropriate wayTrillions of individual bacteria are in the gut, meaning the human to describe the path of this nerve. It runs from the brain stembody contains more bacteria just in the gut than cells in the to the transverse colon. Along the way, it innervates the larynx,entire body.The gut micro-LEGAL Q&A CHIROASSIST biome weighs esophagus, lungs, trachea, heart, and most of the digestive tract. The brain and gut feed-back and feed-forward loops are linkedin at about Executive Directors Update by the vagus nerve. three pounds. The long, convoluted pathway means the vagus is the main nerveIt contains 20 of the parasympathetic nervous system, often called the rest andmillion bacteria digest system. This is the autonomic system that helps the bodygenes; the conserve energy by slowing the heart rate (rest). The vagus nervehuman body has modulates digestion through the migrating motor complex andonly about two Legislative Update relaxes the ileocecal valve and other sphincter muscles in the gutthousand. And (digest). The messages the vagus nerve transmits to the brainthe gut contains INSURANCE Update INSURANCE Update from the gut microbiome also impact the hypothalamus-pituitaryfar more axis, which in turn controls the neuroendocrine system, mood,neurotransmitter TECHNIQUE Council chemicals than and the immune response. Talking bout You the brain itself. In fact, about 90 The vagus nerve link is bidirectional. About 80 percent of thepercent of the messages sent along the vagus superhighway go from the gut tobodys serotonin the brain; about 20 percent go in the other direction. What areis produced MedicareQ&AMedicare Update they talking about? in the gut by OUR HEALTH enterochromaffin Signals from the gut microbiome and from the gut itself tell the brain whats going on down there; signals from the brain tell the(EC) cells. The gut what changes to make in response. The gut tells the brainprocess is highly about the production, expression, and turnover of neurotrans- dependent on mitters such as serotonin and GABA and growth factors such asthe presence of BDNF (brain-derived neurotrophic factor). The gut also reports ongut bacteria. The the production of intestinal barrier chemicals and tight junctionbacteria grow integrity, the modulation of enteric sensory afferents, bacterialand produce metabolites, and mucosal immune regulation. The brain respondsmetabolites with messages that tell the gut to alter mucus and biofilmwithin the gut production, motility, intestinal permeability, and immune function.that stimulate the EC cells to produce serotonin. For example, when vagus afferent nerve fibers within the gutGut bacteria metabolites may also be important in a number detect inflammatory cytokines and other indicators, such asof neurodegenerative diseases. In autism, for example, gut tumor necrosis factor, created by the gut bacteria, they pass themicrobiota appear to alter the immune system and metabolism. message to the brain. The brain responds by stimulating thePeople with autism often have higher intestinal permeability and production of anti-inflammatory neurotransmitters that regulateshow a higher antigenic load from gut bacteria. Their gut biome the immune response.bacteria are less diverse, and Candida is twice as abundant. 16 I Fall 2019 www.anjc.info'