GCG and nutritional deficiency disease: Preserving the continuity of the digestive tract by avoiding tissue removal reduces the risk of severe malnutrition caused by complete emptying. This approach shortens the metabolic pathways for undigested and digested food in the intestines, rapidly stimulating endogenous secretion of GLP-1 from L-cells in the terminal ileum and proximal colon. Postoperative GLP-1 levels can increase by 5-8 times compared to baseline levels.