Does Gastric Surgery (Such as Bariatric Surgery) Impact the Risk of Intestinal Inflammation?

The prevalence of morbid obesity and inflammatory bowel disease (IBD) is on the rise in association with a Western lifestyle. Both conditions are characterized by chronic inflammation. Bariatric surgery (BS) is a recommended and widely used approach to address severe obesity and its related comorbidities. Roux-en-Y gastric bypass (RYGBP) and sleeve gastrectomy (SG) are the most frequently performed procedures worldwide. Evidence is scarce on outcomes of BS in IBD patients.

Systemic and adipose-tissue inflammation seems to decrease following BS. Different studies observed decreased serum levels of inflammatory markers (CRP, IL-6, MCP-1, and TNF-α) along with a reduction of insulin resistance both after RYGBP and SG. Several authors documented postbariatric improvement of concomitant chronic inflammatory diseases (rheumatoid arthritis, systemic lupus erythematosus, gout, and psoriasis). There are only few retrospective case series on outcomes of BS in IBD patients. These studies reported safety and feasibility of BS and improvement in IBD status, manifested by prolonged disease remission and decreased use of pharmacotherapy. Weight loss outcomes were excellent and similar to those of non-IBD patients. The preferred surgical approach for morbidly obese IBD patients is SG in order to avoid potential drawbacks of RYGBP, such as malabsorption, intestinal manipulation, and augmentation of technical difficulties for future IBD surgery. Seven cases of newly diagnosed IBD after BS have been reported, which are more likely to result from postoperative intestinal microbial dysbiosis than from directly induced inflammation.

This review summarizes the outcomes of BS in IBD patients. SG is the preferable technique for morbidly obese IBD patients, who have potentially a double benefit from BS: weight loss and IBD remission. Further research is necessary to clarify the common pathophysiology of chronic inflammation in morbid obesity and in IBD. Postbariatric changes in gut microbiota should also be assessed to understand whether they promote IBD development or not.