Characterization of gut microbiota in patients with metabolic syndrome candidates for bariatric/metabolic surgery: Preliminary findings of a multi-center prospective study

Abstract

Introduction: gut microbiota (GM) seems to be involved in the pathophysiology and progression of both metabolic syndrome (MS) and obesity. The aim was to investigate GM's composition in patients with severe obesity, candidates for bariatric/metabolic surgery BMS.

Materials and methods: Multicentre, prospective, cohort study, enrolling 84 patients with BMI 40-55 kg/m², divided bymetabolic status (MS) inhealthy(group A), pre-MS (B), or MS (C).

Results: No differences were foundregarding anthropometric,nutritional parameters, except for vitamin D.As a whole the alpha and beta diversity examinations showed no statistical differences in GM profile. A total of 5/7 phyla with relative frequencies were identified above 0.1% (Actinobacteria,Bacteroidetes,Firmicutes,Proteobacteria,Verrucomicrobia).FusobacteriaandPatescibacteriarepresented the less abundant. There were no significant differences in the top ten genera.Data onBacteroidetes(inversely related to triglycerides and LDL and directly related to HDL levels) and onFirmicutes(opposite trend) relative abundances suggest no differences among the three conditions.No correlation between the relative abundance of themain phylaand plasmatic glucose levels was observed.

Conclusions: In a selected cohort of patients with obesity, MS did not affect the preoperative GM's profile. Severe obesity, per se, seems to be an independent condition affecting GM.

Keywords: Bariatric/metabolic surgery; Gastric bypass; Gut microbiota; Metabolic syndrome; Obesity.