The role of gut microbiota and amino metabolism in the effects of improvement of islet β-cell function after modified jejunoileal bypass

The change in gut microbiota is an important mechanism of the amelioration of type 2 diabetes mellitus (T2DM) after bariatric surgery. Here, we observe that the modified jejunoileal bypass effectively decreases body weight gain, fasting blood glucose, and lipids level in serum; additionally, islet β-cell function, glucose tolerance, and insulin resistance were markedly ameliorated. The hypoglycemic effect and the improvement in islet β-cell function depend on the changes in gut microbiota structure. modified jejunoileal bypass increases the abundance of gut Escherichia coli and Ruminococcus gnavus and the levels of serum glycine, histidine, and glutamine in T2DM rats; and decreases the abundance of Prevotella copri and the levels of serum branched chain amino acids, which are significantly related to the improvement of islet β-cell function in T2DM rats. Our results suggest that amino acid metabolism may contribute to the islet β-cell function in T2DM rats after modified jejunoileal bypass and that improving gut microbiota composition is a potential therapeutic strategy for T2DM.

Revisional Bariatric Surgery

The annual volume of bariatric surgery is growing, giving rise to an increase in complications requiring complex management, including revision. Bariatric revision procedures are also becoming increasingly necessary for weight-loss recidivism and patients at the extreme of obesity. This chapter outlines clinical management pathways used to address secondary bariatric surgery. It summarizes reasons for, and outcomes with, revision of a laparoscopic gastric band, vertical banded gastroplasty, sleeve gastrectomy, or Roux-en-Y gastric bypass. Surgical techniques used to manage weight regain or failed weight loss after bariatric surgery are also discussed. Finally, surgical solutions for bariatric surgery-induced malnutrition are described, particularly in the setting of biliopancreatic diversion, duodenal switch, or jejunoileal bypass. Overall, the chapter concludes that standardization of revisional procedures can have a significant patient impact, and guidelines must be evidence-based in order to ensure patient safety and success.

Complications of Jejunoileal Bypass

Jejunoileal bypass (JIB) was a malabsorptive bariatric procedure developed in the 1950s based on pioneering work in canine models. All described variants involved anastomosis between the proximal jejunum and terminal ileum. Long-term weight loss and improvement in hyperlipidemia were found to be particularly impressive. However, it became clear by the 1980s that morbidity and mortality associated with JIB were unacceptably high. The procedure was abandoned, and many patients underwent reversal to normal intestinal continuity, or revision to other bariatric procedures. Two main mechanisms underlie the complications with JIB. Malabsorption caused excessive diarrhea, nutritional and metabolic failure, and hyperoxaluria, leading to urolithiasis. Bacterial overgrowth in the defunctioned small intestine was thought to lead to immune complex-mediated development of inflammatory arthritis, and the so-called bypass enteritis syndrome. A combination of these two mechanisms was thought to be responsible for hepatic dysfunction and failure after JIB.