Impact of bariatric surgery on type 2 diabetes: contribution of inflammation and gut microbiome?

Abstract

Obesity is a chronic low-grade inflammatory disease (both at the systemic and adipose tissue level) that continues to rise worldwide. It is associated with an abundance of comorbidities, including type 2 diabetes (T2D). Bariatric surgery, which induces modifications of the intestinal tract, is to date the most successful treatment for obesity. Its use has dramatically increased in number as it enables both weight reduction and metabolic improvements, with 60% of patients even achieving diabetes remission. Several mechanisms are actually demonstrated to be involved in those clinical improvements. Importantly, both obesity and T2D share many phenotypic characteristics, including increased systemic and adipose tissue inflammation, as well as gut microbiota dysbiosis. These characteristics are deeply modulated after bariatric surgery. This review will specifically focus on the host metabolic changes induced by bariatric surgery in regards of the induced gut architectural changes, as well as on the modifications in the inflammatory tone and gut microbiota observed subsequently to bariatric surgery induced weight loss.

Comparison of the effect of Roux‐en‐Y gastric bypass and sleeve gastrectomy on remission of type 2 diabetes: A systematic review and meta‐analysis of randomized controlled trials

“…Moreover, some studies indicate that exclusion of duodenal nutrient exposure is responsible for the weight‐loss–independent effects on glucose homeostasis immediately after RYGB, but the results are inconsistent . Bariatric surgery is also accompanied by changes in other gut‐derived and pancreatic‐derived hormones and changes in the microbial composition, which directly or indirectly may influence glycaemic control.…”

Projection of gut microbiome pre and post-bariatric surgery to predict surgery outcome

“…One of the mechanisms proposed for the effectiveness of bariatric surgeries is the changes in microbiome which influence the bile acids composition leading to metabolic improvement (12,13). This can also occur the other way around, changes in bile acids, pH, and hormone levels lead to a change in the microbiome which affects energy homeostasis (14).…”

Brunner’s Gland Hyperplasia in a Patient after Roux-Y Gastric Bypass: An Important Pitfall in GLP-1 Receptor Imaging

“…Whether these murine data translate to humans and whether ligands other than GLP-1 play a role remain uncertain [24]. It is conceivable that in patients with PBH, increased GLP-1 levels but also other incretins such as GLP-2 with trophic effects may also lead to hyperplasia of Brunner's glands, as observed in this patient [25,26]. However, the distinct pathophysiological role and the interrelationship between GLP1, GLP-1 receptors, and hyperplasia of Brunner's glands remain to be determined.…”