Small bowel absorption after Roux-en-Y gastric bypass

Abstract

Abstract Introduction: Obesity affects 30% of US population. For those patients refractory to conventional weight-loss therapy, Roux-en-Y gastric bypass operation (RYGB) is a proven method to induce sustained weigh-loss, although the mechanisms of weight loss remain speculative. We hypothesize that RYGB in a rat model induces a decrease in small bowel absorption, contributing to weight loss. Methods: Fourteen 3–4 weeks old Sprague Dawley (SD) pups, weighing 73 ± 0.9g were made obese by feeding a high-energy diet for 12 weeks. They were randomly divided into two groups (n = 7/gp): RYGB and Sham Operated obese (SO-obese). Postoperatively, body weight (BW), food intake (FI) and weight of the feces were measured daily for 4 weeks, following which small bowel absorption was measured using D-xylose. Data are expressed in M+-SE and were analyzed using ANOVA and Mann Whitney test. Results: Pre-operative BW of the rats was 757 ± 23g. After 4 weeks, BW in RYGB decrease to 579 ± 10g (24% loss; p Conclusions: RYGB in obese rats reduced BW, decreased FI and small bowel absorption. The reductions of small bowel absorption of nutrients and the increase in fecal volume after RYGB in this rat model contributes to the weight loss observed in diet induced obese rats.