Host-microbe interactions: communication in the microbiota-gut-brain axis.

Animals harbor a diverse array of symbiotic micro-organisms that coexist in communities across different body sites. These microbes maintain host homeostasis and respond to environmental insults to impact host physiological processes. Trillions of indigenous microbes reside in the gastrointestinal tract and engage with the host central nervous system (microbiota-gut-brain axis) by modulating immune responses, interacting with gut intrinsic and extrinsic nervous system, and regulating neuromodulators and biochemicals.