Proximal Small Intestine Bypass Outperforms Roux-en-Y and Jejunoileal Bypass in Glucose Regulation in Streptozotocin‑Induced Diabetic Rats

Background This study aimed to compare the efficacy of modified proximal small intestine bypass (PSIB), Roux-en-Y gastric bypass (RYGB), and conventional jejunoileal bypass (JIB) in weight loss and glucose metabolism in streptozotocin (STZ)-induced diabetic rats. Methods Rats with STZ-induced diabetes were randomly divided into PSIB, RYGB, JIB, and sham-operated (sham) groups. Body weight, food intake, fasting blood glucose (FBG) level, oral glucose tolerance test (OGTT), insulin tolerance test (ITT), liver function, and blood lipids were measured in rats in each group from 1 to 6 weeks after surgery. Results No significant difference in the body weight of the rats in the PSIB and RYGB groups was observed postoperatively, whereas the body weight of the rats in the JIB group was significantly lower. The food intake of the rats in all three surgical groups was significantly less than that in the sham group. The PSIB group had a better glucose-lowering effect than the RYGB and JIB groups. Glucose tolerance improved significantly in all three surgical groups at 2 weeks postoperatively; with improved glucose tolerance in the PSIB group than in the RYGB and JIB groups. At postoperative week 2, insulin sensitivity improved only in the PSIB group; however, by postoperative week 6, insulin sensitivity improved significantly in both the PSIB and JIB groups. Conclusion PSIB demonstrated excellent hypoglycemic effects and OGTT improvements in the early postoperative period, with better efficacy than that of RYGB and JIB. Compared with PSIB and RYGB, conventional JIB was more effective for weight loss.