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

• Main Authors: Sunaina Rengarajan, Kathryn A. Knoop, Arvind Rengarajan, Jiani N. Chai, Jose G. Grajales-Reyes, Vijay K. Samineni, Emilie V. Russler-Germain, Prabha Ranganathan, Alessio Fasano, Gregory S. Sayuk, Robert W. Gereau, IV, Andrew L. Kau, Dan Knights, Purna C. Kashyap, Matthew A. Ciorba, Rodney D. Newberry, Chyi-Song Hsieh
• Format: Article
• Language: English
• Published: Elsevier 2020-10-01
• Series: Cell Reports Medicine
• Subjects: stress; host:commensal immunity; IgA; irritable bowel syndrome
• Online Access: http://www.sciencedirect.com/science/article/pii/S266637912030166X

Summary: 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.