Impact of SADI-S and SG on gut microbiota composition and host metabolism

Introduction Single-anastomosis duodenal-ileal bypass with sleeve gastrectomy (SADI-S) has emerged as one of the most effective surgical options for managing type 2 diabetes (T2D). However, studies on the intestinal microbiota after SADI-S surgery are limited. Given the important role of the gut microbiota in regulating host metabolism, we investigated the effects of SADI-S and sleeve gastrectomy (SG) on gut microbiota and examined their relationship with host metabolism. Methods Wistar rats with diabetes were randomly assigned to the following groups: SADI-S, SG, and the sham operation group (SO). Metabolic effects and gut microbiota characteristics were analysed five weeks after surgery. Results The fasting blood glucose and glycated hemoglobin levels in the SADI-S group and the SG group were significantly lower than those in the SO group (p < 0.05). Furthermore, the levels in the SADI-S group were also significantly lower than those in the SG group (p < 0.05). In addition, the species richness and diversity of the SG group were significantly higher than those of the SADI-S and SO groups (p < 0.05). Moreover, rat glucose metabolism parameters showed a positive correlation with the abundance of 11 bacterial species, including Ruminococcus gauvreauii group, and a negative correlation with the relative abundance of 7 bacterial species, including Enterococcus. Conclusion SADI-S and SG significantly changed the composition of gut microbiota in T2D rats and also improved host metabolism. These alterations in intestinal microbiota may elucidate the mechanisms through which SADI-S and SG improve T2D. Future research is warranted to validate these findings further.