A Potential Role for Stress-Induced Microbial Alterations in IgA-Associated Irritable Bowel Syndrome with Diarrhea.

Stress is a known trigger for flares of inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS); however, this process is not well understood. Here, we find that restraint stress in mice leads to signs of diarrhea, fecal dysbiosis, and a barrier defect via the opening of goblet-cell associated passages. Notably, stress increases host immunity to gut bacteria as assessed by immunoglobulin A (IgA)-bound gut bacteria. Stress-induced microbial changes are necessary and sufficient to elicit these effects. Moreover, similar to mice, many diarrhea-predominant IBS (IBS-D) patients from two cohorts display increased antibacterial immunity as assessed by IgA-bound fecal bacteria. This antibacterial IgA response in IBS-D correlates with somatic symptom severity and was distinct from healthy controls or IBD patients. These findings suggest that stress may play an important role in patients with IgA-associated IBS-D by disrupting the intestinal microbial community that alters gastrointestinal function and host immunity to commensal bacteria.
Competing Interests: DECLARATION OF INTERESTS The authors declare no competing interests. D.K. serves as Senior Scientific Advisor to Diversigen, a company involved in the commercialization of microbiome analysis. Diversigen is now a wholly owned subsidiary of OraSure. P.C.K. is on the advisory board of Novome Biotechnologies and is an ad hoc consultant for Pendulum Therapeutics, IP Group, and Otsuka Pharmaceuticals. These interests have been reviewed and managed by the respective institutions in accordance with their conflict-of-interest policies.