Abstract
PURPOSE: Evidences about the gut microbiota role in weight loss after bariatric surgery (BS) are growing. The objective of this study was to observe the changes of gut microbiota after sleeve gastrectomy (SG) and SG plus truncal vagotomy (SG-TV) and identify specific microbes that may contribute to the improvement of obesity after surgeries. MATERIALS AND METHODS: Forty high-fat diet-induced obesity (DIO) mice were randomized to SG, SG-TV, or sham operation (SH) groups. Body weight (BW) and fast blood glucose (FBG) were measured before and 1, 2, 4, 8, and 12 weeks post-operatively. Fecal samples were collected before and at post-operative week 12 and profiled using 16S rRNA relative and absolute quantitative sequencing. RESULTS: After the surgery, the SG and SG-TV surgeries significantly reduce BW and FBG levels compared with SH, and the SG-TV achieved better effects than SG. A decreasing trend in alpha diversity of gut microbiota and significant changes in taxonomic composition were observed after surgeries. Then, we identified a set of microbes and pathways significantly different in abundance after BS. The genus Parabacteroides and one pathway (polyketide sugar unit biosynthesis) increased in SG-TV group specially, which was also negatively correlated with BW and FBG. CONCLUSION: SG and SG-TV indeed achieve effects of weight loss, but TV could enhance the efficacy of SG. The identified different microbes and pathways, like Parabacteroides, polyketide sugar unit biosynthesis, may partly mediate the beneficial effects of BS, and thus possibly contribute to the development of novel bacteria-based therapeutic approaches.