Impact of the gut microbiota on the gut-brain axis in health and disease. It is now generally accepted that a stable gut microbiota is essential for normal gut physiology and contributes to appropriate signaling along the gut-brain axis and, thereby, to the healthy status of the individual (a). On the other hand (b), intestinal dysbiosis can adversely influence gut physiology, leading to inappropriate gut-brain axis signaling and associated consequences for CNS functions and resulting in disease states. Conversely, stress at the level of the CNS can affect gut function and lead to perturbations of the microbiota. (Adapted from: Cryan J, Dinan T. Mind-altering microorganisms: the impact of the gut microbiota on brain and behavior. Nat Rev Neurosci., 13(10):701-12, 2012.).
