Gut microbiota specific signatures are related to the successful rate of bariatric surgery

Abstract

Bariatric surgery (BS) success rates vary in the long-time. A better understanding of weight-loss response may help improve the outcomes of BS. Gut microbiome could be implicated in the successful rate of BS. The aim of the study is to analyze the role of gut microbiome in the successful rate of BS. This is a cross-sectional study of a prospective cohort of 24 patients who underwent gastric bypass. Patients were classified based on excess weight loss (EWL) as: Success (EWL50% at nadir weight and throughout follow-up), Primary Failure (EWL<50% at nadir weight and thereafter), and Weight Regain (EWL>50% at nadir weight, but <50% at last follow-up visit). Gut microbiome analysis was assessed by High Throughput Sequencing. Cholesterol metabolism was shown as the most affected parameter among groups. Studied groups registered minor changes between their gut microbiome abundances, with Butyrivibrio, Lachnospira and Sarcina among them. However, Success group shared a more diverse core microbiome than the other groups. We showed evidence of a possible role of gut microbiome in the cholesterol metabolism, possibly through bile acids, relative to the success or failure of BS outcomes. Acinetobacter and Serratia, from Primary Failure core microbiome, could have implications in its successful rate. Sarcina abundance was presented as the best genera related to the body mass index (BMI) post-surgery. Gut microbiota could mediate, at least partially, the success rate of BS through their interaction with the bile acids milieu. Further studies are necessary to validate this probe of concept.

Keywords: Bariatric surgery; RYGB; bile acids; cholesterol; gut microbiota.

Figure 1

Retrospective BMI record according to the study groups. Circle: Success, square: Primary Failure, triangle: Weight Regain. *Indicates statistical differences between Success and Primary Failure groups. $ Indicates statistical differences between Success and Weight Regain groups. ∫Indicates statistical differences between Primary Failure and Weight Regain groups.

Figure 2

A. Clustering of fecal bacterial communities according to the different study groups by Principal Coordinates Analysis (PCoA) using Unweighted UniFrac distances. B. Chao1 Richness estimator and Shannon Diversity indexes of the study groups at the StudyTime. Black: Success, grey: Primary Failure, dark grey: Weight Regain.

Figure 3

A. Phylum level distribution of bacteria in fecal samples from the study groups. B. Genera statistically significant among the groups of study.

Figure 4

Venn diagram of the core microbiomes from the study groups at taxa level.

Figure 5

Predictive functionality of gut microbiome. A. Chao1 Richness estimator and Shannon Diversity indexes of the study groups at the StudyTime. B. Predictive values of the bacterial bile salt hydrolase (BSH) enzyme and its distribution among the different phyla. Black: Success, grey: Primary Failure, dark grey: Weight regain.