Diabetes is a common disease, and more than 90% of them are type 2 diabetes. Current treatments include diabetes self-management and education (diet, physical activity, lifestyle interventions, etc.), oral hypoglycemic drugs, and insulin therapy, but the results are not very satisfactory. Pancreatic transplantation and islet cell transplantation methods have limited their clinical application and effectiveness due to many factors such as graft rejection, side effects of immunosuppressive drugs and surgical complications. Embryonic stem cells and pancreatic stem cells, in turn, have been affected by ethical controversies and inconvenience in obtaining materials, respectively. In recent years, domestic and international studies have found that some bariatric surgery can treat type 2 diabetes and reduce various complications of diabetes, opening up new avenues for the surgical treatment of type 2 diabetes. Among them, it was found that 91% of 298 diabetic patients were reversed after treatment with laparoscopic Roux-en-Y gastric bypass (LRYGB); similarly, 86% of 353 hypertensive patients had their blood pressure restored to normal level. Currently laparoscopic Roux-en-Y gastric bypass is one of the two most popular surgical procedures in bariatric surgery in the United States; others include laparoscopic adjustable banded gastric reduction and laparoscopic sleeve gastrectomy, both of which have been shown to be effective in treating type 2 diabetes. Roux-en-Y gastric bypass results In 2004, foreign scholars Cummings et al. reviewed five published papers on 3568 patients with type 2 diabetes who underwent RYGB and found that 82-98% of patients returned to normal blood glucose after surgery, and almost all patients with reduced glucose tolerance shifted to the normal range after surgery. weight loss after RYGB ranged from 35% to 60% and was The insulin sensitivity of patients with weight loss after RYGB increased 4 to 5 times. Surprisingly, long-term investigations have shown that RYGB surgery not only controls blood glucose in patients with type 2 diabetes, but also prevents progression to type 2 diabetes in patients with obesity and impaired glucose tolerance, and reduces complication and mortality rates in patients with type 2 diabetes. McDonald et al. found that the annual mortality rate was only 1% in the surgical group compared with 4.5% in the control group (p<0.0001), and the complication rate was reduced by 75% in the surgical group compared with the non-surgical group. Numerous studies have shown that RYGB significantly improves glycemia and glucose tolerance in obese patients with combined type 2 diabetes, and that a significant number of patients do not require medication to lower glucose and maintain normoglycemia over time after surgery. Indications for surgery There are no specific and widely accepted criteria for the indications for surgery. Some scholars believe that surgery is indicated for obese patients with BMI>35 kg/m2 combined with type 2 diabetes; others believe that early surgical intervention is advisable for patients with type 2 diabetes without serious complications and with disease duration <5 years. The earlier surgery is performed in obese patients with combined type 2 diabetes, the greater the possibility of normalizing blood glucose, while the efficacy is poor in those with long duration of disease, which may be related to whether β-cell function can be fully restored.