Gut Microbiome and Mental Stress-Related Disorders: The Interplay of Classic and Microbial Endocrinology

Abstract

The gastrointestinal (GI) tract contains its own autonomic “enteric nervous system”, which is in dynamic homeostasis with the central nervous system of the organism, forming with it the so-called gut-brain axis. The GI tract, however, contains the gut microbiome, a remarkable “organ”, irrevocably connected to its function and hence also to that of the gut-brain axis. The stress system of the organism, through its end-hormones, influences the gut–brain-gut microbiome axis, in various ways. Microbial endocrinology suggests that microorganisms carry receptors with high affinity for stress hormones, which may serve as organismal cues for the sustenance, reproduction, symbiotic functions and/or the virulence of the gut microorganisms. The gut microbiome may, thus, have a role in the onset, course and symptomatology of various stress-related mental health disorders. In this chapter, we review the latest findings on the interconnection of the gut microbiome and some stress-related mental disorders, under the light of Microbial Endocrinology.