Background: Excluding the foregut (distal stomach and duodenum) from food transit in RYGB normalizes glucose tolerance. Excluding/removing the duodenal mucosa partly improves glycemic control. So far, the effect of excluding/removing the gastric mucosa remains unknown.
Objective: To observe the effect of removing the distal gastric mucosa on glucose tolerance.
Method: Thirty fatty Sprague-Dawley rats received low-dose streptozotocin (STZ) to induce type 2 diabetes (T2D), then randomly assigned to Roux-en-Y gastric bypass (RYGB, n = 8), distal gastric mucosa removal (DGMR, n = 8), duodenal-jejunal bypass (DJB, n = 8), and Sham (n = 6) groups. In the DGMR group, the distal third of the gastric mucosa was removed by thermal ablation using an electrocautery. Rats were followed for 8 weeks postoperatively. Preoperative oral glucose tolerance test (OGTT), insulin tolerance test (ITT), and mixed-meal tolerance test (MMTT) were repeated 3 and 6 weeks postoperatively. Changes in body weight, food intake, and fasting blood glucose were also recorded.
Results: Gastrin AUC decreased significantly (p < 0.05) in the DGMR group after surgery. A significantly increased GLP-1 AUC was found in the RYGB, DGMR, and DJB groups at week 3 and only the RYGB group at week 6 postoperatively. The improved glucose tolerance in the RYGB group was significantly greater than the improved glucose tolerance in the DGMR and DJB groups. The improved glucose tolerance 3 and 6 weeks after surgery in the DGMR group was significantly greater than the improved glucose tolerance in the DJB group. Body weight decreased significantly in the RYGB, DGMR, and DJB groups postoperatively.
Conclusion: Removing the distal gastric mucosa induced significant weight loss and improved glycemic control in T2D SD rat model. Therefore, the gastric mucosa exclusion in RYGB may be key to the weight loss and diabetes remission, which perhaps warrants a new theory.
Keywords: Foregut; GLP-1; Gastric bypass; Gastric mucosa; Gastrin; Type 2 diabetes.