ObjectiveTo compare the effect of ileal transposition (IT) and Roux-en-Y gastric bypass (RYGBP) on blood glucose and expression of glucagon-like peptide-1 (GLP-1) in Goto-Kakizaki (GK) rats with non-obese type 2 diabetes mellitus (T2DM). MethodsThirty male GK rats were randomized divided into three groups:IT group (n=10), RYGBP group (n=10), and Sham group (n=10). The mortality and complication were observed after surgery. The levels of fasting blood glucose (FBG), fasting insulin (FINS), glycosylated hemoglobin (HbA1c), and GLP-1 were determined before operation, and 1 week, 2 weeks, 1 month, 2 months, 3 months, 6 months after operation in the GK rats of 3 groups. Results① Mortality and morbility. There was no death and complication occurred in IT group and Sham group, only 5 rats of RYGBP group suffered from complication, and 2 of them died. The mortality and morbility were higher in RYGBP group than those of IT group and Sham group (P < 0.05). ② FBG. Compared with before operation in the same group, the FBG levels of IT group and RYGBP group in 1 week, 2 weeks, 1 month, 2 months, 3 months, and 6 months after operation were all lower (P < 0.05). In 1 week, 2 weeks, 1 month, 2 months, 3 months, and 6 months after operation, FBG levels of IT group and RYGBP group were all lower than those of Sham group at the same time point (P < 0.05), but there was no significant difference between IT group and RYGBP group at the 6 time points (P > 0.05). ③ FINS and HbA1c. Compared with before operation in the same group, the FINS levels of IT group and RYGBP group in 3 months and 6 months after operation were higher than those of Sham group (P < 0.05), HbA1c levels of IT group and RYGBP group were both lower at the 2 time points (P < 0.05). In 3 months and 6 months after operation, FINS levels of IT group and RYGBP group were both higher, and HbA1c levels were both lower than corresponding indexes of Sham group at the same time point (P < 0.05), but there was no significant difference between IT group and RYGBP group at the 2 time points (P > 0.05). ④ GLP-1. Compared with before operation in the same group, the GLP-1 levels of IT group and RYGBP group in 1 week, 2 weeks, 1 month, 2 months, 3 months, and 6 months after operation were all higher (P < 0.05). In 1 week, 2 weeks, 1 month, 2 months, 3 months, and 6 months after operation, GLP-1 levels of IT group and RYGBP group were both higher than those of Sham group at the same time point (P < 0.05), but there was no significant difference between IT group and RYGBP group at the 6 time points (P > 0.05). ConclusionIT and RYGBP have a significant hypoglycemic effect on non-obese T2DM GK rats, but IT has lower mortality and morbility, which is more effective and safer, comparing with RYGBP.