Probiotics, psychobiotics, and metabiotics: problems and prospects

A large number of recent works deal with the microbiota of the human organism. Of paramount importance is the microbiota of the gut, especially of its “densely populated” distal part, the colon. In the literature, the gut is considered the largest digestive, immune, and endocrine organ. The functioning of the microbiota involves the production of numerous low molecular weight compounds that represent biochemical effectors, co-factors, or signals. An important role is performed by neurochemicals. In order to ameliorate the human organism’s microbial ecology, various drug preparations, biologically active additives, and functional food products are used. Currently popular preparations include selected strains of lactobacilli, bifidobacteria, bacilli, and other live microorganisms (probiotics) and biologically active substances (metabiotics) that result from the metabolic activities of symbiotic microorganisms. Probiotics include a subgroup denoted as psychobiotics that, when applied in adequate amounts, ameliorate the health of patients with psychiatric problems.