Laparoscopic sleeve gastrectomy for morbid obesity improves gut microbiota balance, increases colonic mucosal-associated invariant T cells and decreases circulating regulatory T cells

Background Laparoscopic sleeve gastrectomy (LSG) for morbid obesity may improve gut microbiota balance and decrease chronic inflammation. This study examines the changes in gut microbiota and immune environment, including mucosal-associated invariant T cells (MAIT cells) and regulatory T cells (Treg cells) caused by LSG. Methods Ten morbidly obese patients underwent LSG at our institution between December 2018 and March 2020. Flow cytometry for Th1/Th2/Th17 cells, Treg cells and MAIT cells in peripheral blood and colonic mucosa and 16S rRNA analysis of gut microbiota were performed preoperatively and then 12 months postoperatively. Results Twelve months after LSG, the median percent total weight loss was 30.3% and the median percent excess weight loss was 66.9%. According to laboratory data, adiponectin increased, leptin decreased, and chronic inflammation improved after LSG. In the gut microbiota, Bacteroidetes and Fusobacteria increased after LSG, and indices of alpha diversity increased after LSG. In colonic mucosa, the frequency of MAIT cells increased after LSG. In peripheral blood, the frequency of Th1 cells and effector Treg cells decreased after LSG. Conclusions After LSG for morbid obesity, improvement in chronic inflammation in obesity is suggested by change in the constituent bacterial species, increase in the diversity of gut microbiota, increase in MAIT cells in the colonic mucosa, and decrease in effector Treg cells in the peripheral blood. [Graphics] .

Automated summary

This study examines the changes in gut microbiota and immune environment caused by laparoscopic sleeve gastrectomy (LSG) in morbidly obese patients. It found that LSG improved chronic inflammation in obesity by changing the composition and diversity of gut microbiota, increasing the frequency of MAIT cells in the colonic mucosa, and decreasing the frequency of Th1 cells and effector Treg cells in the peripheral blood.