Gut microbiota after Roux‐en‐Y gastric bypass and sleeve gastrectomy in a diabetic rat model: Increased diversity and associations of discriminant genera with metabolic changes

Abstract

Recent work with gut microbiota after bariatric surgery is limited, and the results have not been in agreement. Given the role of the gut microbiota in regulating host metabolism, we explored the effect of Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) on the modifications of gut microbiota with regard to the potential influence of food intake and/or weight loss and examined their links with host metabolism. Zucker diabetic fatty rats were divided into the following groups: RYGB; sham-operated with pair-fed as RYGB; sham-operated fed ad libitum; and SG. The metabolic effects and gut microbiota profile were analyzed 10 weeks postoperatively. Associations between discriminating genera and metabolic markers after RYGB were explored. The 2 procedures induced similar glucose improvement and increased flora diversity after 10 weeks compared with sham-operated groups. RYGB induced a marked higher relative abundance of Proteobacteria/Gammaproteobacteria and Betaproteobacteria and increased emergence of Fusobacteria and Clostridium, whereas SG resulted in more abundant Actinobacteria compared with other groups. Most of the 12 discriminant genera correlated with changes in metabolic phenotype, but only 28.6% of these correlations were independent of weight, and 4 discriminant genera still negatively correlated with serum insulin level independent of food intake and weight loss after RYGB. These data demonstrate that RYGB and SG surgery produced similar diversity but different microbiota compositions changes in Zucker diabetic fatty rats. These findings stimulate deeper explorations of functions of the discriminate microbiota and the mechanisms linking postsurgical modulation of gut microbiota and improvements in insulin resistance.

Roux‐en‐Y gastric bypass decreases endotoxemia and inflammatory stress in association with improvements in gut permeability in obese diabetic rats

“…Some studies have suggested that this downregulation is related to the upregulation of gastrointestinal hormones, such as glucagon‐like peptide‐1 (GLP‐1), after RYGB surgery . In preliminary studies, we found that RYGB induced a significant increase in the relative abundance of the classes Gammaproteobacteria and Betaproteobacteria, both of which belong to the phylum Proteobacteria . However, Proteobacteria are not generally considered beneficial because of their proinflammatory properties .…”

“…Six‐week‐old specific pathogen‐free male ZDF rats were used in these experiments. The experimental groups were similar to those in our previous study . Briefly, 30 rats were randomly assigned to one of three groups: and RYGB group (RY), a sham‐operated and pair‐fed group (PF), and a sham‐operated group fed ad libitum (AL).…”

“…Briefly, 30 rats were randomly assigned to one of three groups: and RYGB group (RY), a sham‐operated and pair‐fed group (PF), and a sham‐operated group fed ad libitum (AL). Details of the RYGB and sham surgical procedures have been reported elsewhere . This study was performed with the approval of the Animal Care and Experimentation Committee, Second Military University.…”

“…providing a quite precise approximation of obesity associated with T2D in humans. Based on a previous study on the relationship between metabolism and gut microbiota following RYGB, in this study we further investigated the levels of inflammation and gut permeability after RYGB in ZDF rats and explored the relationship between inflammatory status and intestinal barrier integrity represented by specific tight junction proteins.…”

Impact of Roux-En-Y Gastric Bypass Surgery on Neurohormonal and Gastrointestinal Physiology: Insights for Future Weight Loss Efforts

“…Similar gut microbial changes were seen after non-surgical weight loss [112,118]. Unlike in non-surgical weight loss, there was an increased abundance of Proteobacteria, specifically Escherichia coli, after RYGB [115][116][117][119][120][121][122][123]. Enterobacteriaceae and Pasteurellaceae were also associated with weight loss after RYGB [122,123].…”