Background: Autoimmune phenotypes are prevalent in major psychiatric disorders.
Disequilibria of cellular processes occurring in the gastrointestinal (GI) tract likely
contribute to immune dysfunction in psychiatric disorders. As the venue of a complex community
of resident microbes, the gut in a homeostatic state equates with a functional digestive
system, cellular barrier stability and properly regulated recognition of self and non-self
antigens. When gut processes become disrupted as a result of environmental or genetic
factors, autoimmunity may ensue.
Methods: Here, we review the issues pertinent to autoimmunity and the microbiome in
psychiatric disorders and show that many of the reported immune risk factors for the development
of these brain disorders are in fact related and consistent with dysfunctions occurring
in the gut. We review the few human microbiome studies that have been done in people
with psychiatric disorders and supplement this information with mechanistic data gleaned
from experimental rodent studies.
Results: These investigations demonstrate changes in behavior and brain biochemistry directly attributable to
alterations in the gut microbiome. We present a model by which autoantigens are produced by extrinsicallyderived
food and microbial factors bound to intrinsic components of the gut including receptors present in the
enteric nervous system.
Conclusion: This new focus on examining activities outside of the CNS for relevance to the etiology and pathophysiology
of psychiatric disorders may require new modalities or a re-evaluation of pharmaceutical targets found
in peripheral systems.
Keywords: Microbiota, schizophrenia, autism, psychosis, NMDA receptor, bacteria, virus, gluten, celiac disease, gut-brain axis.
Rights & PermissionsPrintExport