Microbiome and brain: gut microbiota and neuroendocrine system

The microbial ecosystem that inhabits the gastrointestinal tract of all mammals, the gut microbiota, has been in a symbiotic relationship with its hosts for millennia. Thanks to modern technology, many bodily functions are being elucidated that are controlled or modulated by the gut microbiota. One of the systems closely interrelated with the gut microbiota is the neuroendocrine system that controls various processes in the body in response to stress, namely the hypothalamic-pituitary-adrenal (HPA) axis. This article describes the bi-directional relationship between the gut microbiota and the HPA axis, discusses the underlying mechanisms and links to other body systems such as the immune, autonomic, central nervous systems, sensory organs, intestinal and blood-brain barriers. The useful role of probiotics and prebiotics, the contribution of taking antibacterial drugs were analyzed.