Gastrointestinal manifestations after Roux-en-Y gastric bypass surgery in individuals with and without type 2 diabetes

Abstract Background Roux-en-Y gastric bypass (RYGB) surgery is an effective treatment for obesity, which improves cardiovascular health and reduces risk of premature mortality. However, some reports have suggested that RYGB may predispose to adverse health outcomes such as increased risk of inflammatory bowel disease (IBD) and colorectal cancer. Objectives The present prospective study aimed to evaluate the impact of RYGB surgery on cardiovascular risk factors and gastrointestinal inflammation in individuals with and without type 2 diabetes mellitus (T2DM). Setting The study was performed at a university hospital setting in Finland. Methods Blood and fecal samples were collected at baseline and six months after surgery from 30 individuals, of which sixteen had T2DM and fourteen were non-diabetics. There were also single study visits for six healthy reference subjects. Changes in cardiovascular risk factors, serum cholesterol, and triglycerides were investigated before and after surgery. Fecal samples were analyzed for calprotectin, anti-saccharomyces IgA antibodies (ASCA), active lipopolysaccharide (LPS) concentration, short-chain fatty acids (SCFAs), intestinal alkaline phosphatase (IAP) activity, and methylglyoxal-hydro-imidazolone (MG-H1) protein adducts formation. Results After RYGB, body weight decreased on average -21.5% (-27.2±7.8 kg), excess weight loss (EWL) averaged 51% and there were improvements in cardiovascular risk factors. Fecal calprotectin levels (p Conclusion The intestinal homeostasis is altered after RYGB with several fecal markers suggesting increased inflammation, however, clinical significance of the detected changes is currently uncertain. As chronic inflammation may predispose to adverse health effects, our findings may have relevance for the suggested association between RYGB and increased risk of incident IBD and colorectal cancer.