ObjectiveTo compare effectiveness of single-anastomosis duodenoileal bypass with sleeve gastrectomy (SADI-S) and single anastomosis sleeve ileal (SASI) bypass on weight loss and glucose regulating as well as difference in micronutrient deficiency in obese rats with type 2 diabetes mellitus. MethodsThirty-six Spraque-Dawley rats fed with high fat diet combined with intraperitoneal injection of low-dose streptozotocin (35 mg/kg) for 1 month were used to induce obese rats with type 2 diabetes mellitus, then were randomly averagely divided into 3 groups: SADI-S group, SASI group, and sham operation (SO) group. Eight rats from numbered rats of each group were randomly selected to carry out experimental observation. The rats’ body weight, food intake, and fasting blood glucose (FBG) were measured from before operation to postoperative 1–6 months. Meanwhile blood was collected before surgery, as well as at month 1 and 6 after surgery for oral glucose tolerance testing (OGTT) and insulin resistance testing (ITT). Serum glucagon-like peptide (GLP-1), hemoglobin, and albumin levels, as well as vitamin B12, calcium, and ferrum concentrations were measured before surgery as well as at month 1 and 6 after surgery. Results① The body weight, food intake (except 5–6 months), and FBG level in the SADI-S group and SASI group were lower than the SO group (P<0.05) from 1- to6-month after operation, and all obviously decreased at month 1 after operation (P<0.05), but there was no statistical differences between the SADI-S group and SASI group (P>0.05). ② The postoperative OGTT and ITT blood glucose levels in the SADI-S group and SASI group were lower than those in the SO group (P<0.05) and were lower than those in the preoperative levels (P<0.05), and the SADI-S group had a lower OGTT blood glucose level than the SASI group at month 6 after operation (P<0.05). ③ The GLP-1 levels of the SADI-S group and SASI group were higher than that of the SO group (P<0.05), and higher than before operation at month 6 after operation (P<0.05) , but there was no statistical difference was found between the SADI-S group and SASI group after operation (P>0.05). ④ The postoperative albumin levels of the SADI-S group and SASI groups= were lower than of the SO group (P<0.05) and were lower than before operation, and albumin level of the SADI-S group was lower than of the SASI group at postoperative month 6 (P<0.05); while the hemoglobin had no statistical differences among the 3 groups (P>0.05). ⑤ The ferrum concentration of the SADI-S group was lower than that of the SASI group and SO group at 1 month after operation (all P<0.05), while it increased slightly at month 6 after operation and had no statistical difference between the SADI-S group and SASI group (P>0.05); the calcium concentrations of the SADI-S group and SASI group only at 6 month after operation were lower than those of the SO group (P<0.05), and were lower as compared with before operation (P<0.05) , but no statistical difference was found between the SADI-S group and SASI group (P>0.05); the vitamin B12 had no statistical differences among the 3 groups (P>0.05). ConclusionsFor obese rats with type 2 diabetes mellitus, SADI-S and SASI have similar weight loss effect. Long-term glucose reduction of SADI-S shows a advantage than SASI, but influence of postoperative micronutrients of SASI is inferior to SASI.