Shifts in intestinal microbiota after duodenal exclusion favor glycemic control and weight loss: a randomized controlled trial.

BACKGROUND: In recent years, studies indicate gut microbiota as an important modulator in the pathophysiology of type 2 diabetes. Environmental and genetic factors interact to control the host's intestinal microbiota, triggering metabolic disorders such as obesity and insulin resistance.

OBJECTIVES: The objective of this study was to identify the fecal microbiota in adult type 2 diabetes patients and to assess changes in composition after metabolic surgery.

SETTING: University Hospital of the University of São Paulo.

METHODS: Twenty-one patients were enrolled in a randomized controlled study divided into 2 arms. One group underwent duodenal-jejunal bypass surgery with minimal gastric resection, and fecal samples were collected before the operation and after 6 and 12 months. The other group received medical care (standard care group) and was followed for 12 months. Fecal samples were collected at baseline and after 6 and 12 months. Fecal microbiota was analyzed using high-throughput sequencing with V4 16 S rRNA primers.

RESULTS: The fecal microbiota in duodenal-jejunal bypass surgery with minimal gastric resection group (Bacteroides, Akkermansia, and Dialister) exhibited increased abundance and diversity compared with that in the standard care group; however, the increase in A. muciniphila was only statistically significant in the surgical group, probably due to the study's small sample size.

CONCLUSIONS: The data presented suggest that duodenal-jejunal bypass surgery with minimal gastric resection increases microbial richness and abundancy, mainly for those bacteria related to weight loss and metabolic control (Akkermansia), providing a better understanding of the role of microbiota in type 2 diabetes regulation and its changes after metabolic surgery.