To establish sleeve gastrectomy (SG) and modified Roux-en-Y gastric bypass (RYGB) model in diet-induced obese (DIO) mice and applying to basic mechanical research on mechanisms of metabolic surgery.

Weight and age matched 5-week-old male C57 BL/6 mice were selected and fed with 60% high fat diet for 8 weeks for induction of type 2 diabetes mellitus. The average weight and fasting plasma glucose levels were (33.79±2.0) g and (11.5±0.8) mmol/L respectively. Mice were randomized into modified SG group (n=7), RYGB group (n=10) and control group (n=6). The first two operations were performed under microscope. Traditional operation techniques were applied for the SG group while the modified RYGB group was treated with lower esophageal ligation and esophago-intestinal anastomosis. Body weight and fasting blood glucose levels were measured pre- and post-operative day (POD) 1, 2, 4, 7 and 14.

The general survival rate of SG group was 85.71% (6/7) and 60% (6/10) in modified RYGB group. SG group and modified RYGB group showed significantly more weight loss and blood glucose reduction than that in control group. SG and modified RYGB groups presented significantly lower body masses at POD 4, 7 and 14 (P<0.05). The fasting blood glucose in the SG group and modified RYGB group was significantly lower than that in the control group (P<0.05).

SG and modified RYGB bypass models were successfully established in DIO mice. Modified RYGB bypass and SG in DIO mice were effective and feasible. They could also provide a more reasonable model for the basic research and better understanding of mechanism of metabolic surgery in those suffered from obesity with type 2 diabetes mellitus patients.