Gut microbiota–brain axis (GBA (sometimes also referred to as MGBA for "microbiota–gut–brain axis"))

The **gut microbiota–brain axis** refers to a complex bidirectional communication network linking the gastrointestinal tract’s resident microorganisms (“gut microbiota”) with the central nervous system. This system integrates neural pathways—including the vagus nerve—immune signals, endocrine factors such as those from the hypothalamic-pituitary-adrenal axis, metabolic products from microbes like short-chain fatty acids and neurotransmitters synthesized by bacteria. The GBA plays key roles in regulating brain physiology, behavior, cognition, stress responses, immune homeostasis, neuroinflammation—and is implicated in various neurological and psychiatric conditions. It is not a single molecular target but an emerging therapeutic concept; interventions aim at modifying this network through dietary changes or manipulation of gut flora using probiotics/prebiotics/fecal transplants rather than direct pharmacological targeting.

Other names

Microbiota–gut–brain axisGut-brain axisGBAMGBA

Modulation of microbial composition to influence metabolite production and immune signaling Alteration of neurotransmitter levels via microbial metabolism Regulation of inflammation through immune pathways and barrier function improvement