At the intersection between neuroscience, microbiology, and psychiatry, the 
enteric microbiome has potential to become a novel paradigm for studying the 
psychobiological underpinnings of mental illness. Several studies provide 
support for the view that the enteric microbiome influences behavior through the 
microbiota-gut-brain axis. Moreover, recent findings are suggestive of the 
possibility that dysregulation of the enteric microbiota (i.e., dysbiosis) and 
associated bacterial translocation across the intestinal epithelium may be 
involved in the pathophysiology of stress-related psychiatric disorders, 
particularly depression. The current article reviews preliminary evidence 
linking the enteric microbiota and its metabolites to psychiatric illness, along 
with separate lines of empirical inquiry on the potential involvement of 
psychosocial stressors, proinflammatory cytokines and neuroinflammation, the 
hypothalamic-pituitary-adrenal axis, and vagal nerve activation, respectively, 
in this relationship. Finally, and drawing on these independent lines of 
research, an integrative conceptual model is proposed in which stress-induced 
enteric dysbiosis and intestinal permeability confer risk for negative mental 
health outcomes through immunoregulatory, endocrinal, and neural pathways. 
(PsycINFO Database Record