Bariatric surgery attenuates colitis in an obese murine model

Abstract Background Obesity and inflammatory bowel disease (IBD) represent chronic inflammatory conditions. Bariatric surgery improves some obesity-related co-morbidities, but the effects of bariatric surgery on IBD have not been well studied. Objectives To examine if bariatric surgery may attenuate colitis in an obese murine model of IBD and study the mechanisms underlying the postsurgical amelioration of intestinal inflammation. Setting University of California Irvine, Department of Surgery and Microbiology laboratories. Methods Obese mice were assigned to one of 2 bariatric procedures [Duodenojejunal Bypass (DJB n=6), Sleeve Gastrectomy (SG n=8)]. Sham-operated mice were (Sham n=8) were used as a control. After recovering from surgery, IBD was induced by administration of 2% dextran sodium sulfate. Fecal samples were collected before and after IBD induction for microbiome analysis. Pathologic analyses and immunohistochemical staining were performed on colon. Results Survival after DJB and SG was higher relative to Sham mice. Histologically, DJB mice had significantly less intestinal inflammation. The observed improvements were not related to a difference in weight among the groups. Farnesoid X receptor staining in the colon was observed quantitatively more in DJB than in SG and sham mice. A statistically significant increase in the number of Lactobacillales was observed in the stool of mice after DJB. Conclusion These results suggest that bariatric surgery, in particular DJB, reduces the severity of colitis in a chemically-induced IBD murine model. The anticolitis effects of DJB may be associated with Farnesoid X receptor regulation and gut microbiome rearrangements.