Sleeve gastrectomy (SG) induces weight loss-independent improvements in glucose homeostasis by unknown mechanisms. We sought to identify the metabolic adaptations responsible for these improvements. Nonobese C57BL/6J mice on standard chow underwent SG or sham surgery. Functional testing and indirect calorimetry were used to capture metabolic phenotypes. Tissue-specific glucose uptake was assessed by 18-fluorodeoxyglucose (18-FDG) PET/computed tomography, and RNA sequencing was used for gene-expression analysis. In this model, SG induced durable improvements in glucose tolerance in the absence of changes in weight, body composition, or food intake. Indirect calorimetry revealed that SG increased the average respiratory exchange ratio toward 1.0, indicating a weight-independent, systemic shift to carbohydrate utilization. Following SG, orally administered 18-FDG preferentially localized to white adipose depots, showing tissue-specific increases in glucose utilization induced by surgery. Transcriptional analysis with RNA sequencing demonstrated that increased glucose uptake in the visceral adipose tissue was associated with upregulation in transcriptional pathways involved in energy metabolism, adipocyte maturation, and adaptive and innate immune cell chemotaxis and differentiation. SG induces a rapid, weight loss-independent shift toward glucose utilization and transcriptional remodeling of metabolic and immune pathways in visceral adipose tissue. Continued study of this early post-SG physiology may lead to a better understanding of the anti-diabetic mechanisms of bariatric surgery.

Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) are the most effective therapies for obesity and may have beneficial effects on the immune system. Therefore, we compared RYGB vs SG outcomes in patients with inflammatory bowel disease (IBD). In this retrospective cohort study, we identified 54 patients with either Crohn's disease (CD; n = 31) or ulcerative colitis (UC; n = 23), diagnosed before bariatric surgery, between 2000 and 2017. Nineteen patients underwent RYGB and 35 patients underwent SG. Patients presenting for RYGB and SG were of similar age (46.2 ± 9.5 years vs 47.2 ± 12.3 years), preoperative BMI (48.5 ± 7.7 kg/m2 vs 44.9 ± 7.3 kg/m2) and IBD status, as measured by medications. Both operations led to significant weight loss at 1 year. After RYGB and SG, there were no significant differences in the proportion of patients with UC who had improved (27% vs 8%), unchanged (64% vs 92%), or worse (9% vs 0%) IBD medication requirements, respectively. Similar analysis in the patients with CD showed no significant differences in the proportion who had improved (37.5% vs 44%), or unchanged (25% vs 52%) IBD-medication requirements after RYGB and SG, respectively. However, there was a significant difference in the proportion of patients who had worsened CD after RYGB compared with SG (37.5% vs 4%; p = 0.016). There was a greater rate of surgical complications after RYGB compared to SG (26% vs. 3%; p = 0.02). A sizable proportion of patients experienced improvements in IBD post-bariatric surgery. However, in CD patients, RYGB was associated with a significantly greater number of patients with increased IBD-medication requirements. Sleeve gastrectomy led to less weight loss, but had a lower rate of severe complications compared with RYGB. In patients with IBD, and particularly CD, SG may be the safer surgery.

This case-control study examines the use of glucagon-like peptide-1 receptor agonist before metabolic and bariatric surgery and its postoperative outcome.