Endocrine Properties of Microbiota

Microbiota and the macroorganism are in constant interactionwith each other. Symbiotic microbiota is implicated in a numberof important physiological, biochemical and neuroendocrine functionsof the macroorganism. Metabolic activity of microbiota in the gastrointestinaltract (GIT) helps digest food, absorb nutrients, and extract energy.Gut microbiota is involved in the processes of protein, fat and carbohydratemetabolism, gluconeogenesis and glycogenolysis, and also influencesthe feelings of hunger and satiety. In addition, microbiota is oftenconsidered as a sort of metabolically active organ, as the powerof gut microbiota metabolic reactions is comparable to that of theliver in the host organism. Microbiota produces autoinducers (quorum-sensingcompounds), hormones, neurotransmitters, short-chain fatty acids(SCFA), secondary bile acids, growth factors, gaseous molecules,and many other active substances. Microbial metabolites providethe main communication between the host organism and its microbialcommunity and are of great importance for the normal functioningof the macroorganism since its intrauterine development up to itsaging. Moreover, changes in metabolic activity and/or the ratioof different types of microorganisms can lead to various metabolicdisorders of the host organism, and vice versa, a metabolic disorderof the host organism can lead to a change in the species composition ofthe microbiota. This review describes the influence of the microbiotaand its metabolites on the neuroendocrine functions of the macroorganismand mechanisms of this influence.