In recent years, numerous scientific articles have been published on the microbiota-gut-brain axis and the medical outcomes that emerge with the two-way interaction. Microbiota balance disorders and increased intestinal permeability and their interactions with systems, especially the brain, have been shown and explained. The relationships of this interaction with many diseases and medical disorders, including pathological changes in the brain in autism and gut microbiota, have been reported. Pathological changes in the brain also affect behavioral disorders. It has been reported that the initiation and triggering of inflammation in the brain is associated with disorders in the gut microbiota content.