Department of Molecular Systems Biology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany.
Institute of Biochemistry, Faculty of Life Sciences, University of Leipzig, Leipzig, Germany.
Microbiome. 2020 Feb 7;8(1):13. doi: 10.1186/s40168-020-0788-1.
Roux-en-Y gastric bypass (RYGB) surgery is a last-resort treatment to induce substantial and sustained weight loss in cases of severe obesity. This anatomical rearrangement affects the intestinal microbiota, but so far, little information is available on how it interferes with microbial functionality and microbial-host interactions independently of weight loss.
A rat model was employed where the RYGB-surgery cohort is compared to sham-operated controls which were kept at a matched body weight by food restriction. We investigated the microbial taxonomy and functional activity using 16S rRNA amplicon gene sequencing, metaproteomics, and metabolomics on samples collected from theileum, the cecum, and the colon, and separately analysed the lumen and mucus-associated microbiota.
Altered gut architecture in RYGB increased the relative occurrence of Actinobacteria, especially Bifidobacteriaceae and Proteobacteria, while in general, Firmicutes were decreased although Streptococcaceae and Clostridium perfringens were observed at relative higher abundances independent of weight loss. A decrease of conjugated and secondary bile acids was observed in the RYGB-gut lumen. The arginine biosynthesis pathway in the microbiota was altered, as indicated by the changes in the abundance of upstream metabolites and enzymes, resulting in lower levels of arginine and higher levels of aspartate in the colon after RYGB.
The anatomical rearrangement in RYGB affects microbiota composition and functionality as well as changes in amino acid and bile acid metabolism independently of weight loss. The shift in the taxonomic structure of the microbiota after RYGB may be mediated by the resulting change in the composition of the bile acid pool in the gut and by changes in the composition of nutrients in the gut. Video abstract.
Roux-en-Y 胃旁路（RYGB）手术是治疗严重肥胖症的最后手段，可以诱导显著和持续的体重减轻。这种解剖学上的重排会影响肠道微生物群，但到目前为止，关于它如何独立于体重减轻来干扰微生物功能和微生物-宿主相互作用的信息还很少。
采用大鼠模型，将 RYGB 手术组与假手术对照组进行比较，假手术对照组通过限制饮食来保持匹配的体重。我们使用 16S rRNA 扩增子基因测序、代谢组学和代谢组学，对取自回肠、盲肠和结肠的样本进行微生物分类群和功能活性研究，并分别分析腔和粘液相关的微生物群。
RYGB 改变的肠道结构增加了放线菌的相对发生率，特别是双歧杆菌科和变形菌门，而总的来说，厚壁菌门减少，尽管链球菌科和产气荚膜梭菌尽管与体重减轻无关，但观察到相对较高的丰度。RYGB 肠道腔中的共轭和次级胆汁酸减少。微生物群中的精氨酸生物合成途径发生改变，表现为上游代谢物和酶的丰度变化，导致 RYGB 后结肠中精氨酸水平降低，天冬氨酸水平升高。
RYGB 的解剖学重排影响微生物群落的组成和功能，以及氨基酸和胆汁酸代谢的变化，而不依赖于体重减轻。RYGB 后微生物群落的分类结构变化可能是由肠道胆汁酸池组成的变化以及肠道中营养物质组成的变化介导的。视频摘要。
