The gut–brain axis is a bidirectional communication system between the central nervous system (CNS) and the gastrointestinal tract.
Regulation of the microbiota–brain–gut axis is essential for maintaining homeostasis, including that of the CNS. A number of approaches have been used to probe this axis, including the use of germ-free animals, probiotic agents, antibiotics, or animals exposed to pathogenic bacterial infections.
Together, it is clear that the gut microbiota can be a key regulator of mood, cognition, pain, and obesity. Understanding microbiota–gut–brain communications is an exciting but challenging area of research that may contribute new insights into individual variations in cognition, personality, mood, sleep, and eating behavior and how they contribute to a range of neuropsychiatric diseases ranging from affective disorders to autism and schizophrenia.












