Endocrine Abstracts

Introduction and Objetive: The composition of human gut microbiota is an emerging field of research and is currently regarded as pathophysiologically linked to obesity. However, we still lack a thorough understanding of what constitutes health and disease in this subject. We present herein a descriptive study of the gut microbiota composition among Spanish morbidly obese subjects, clustered regarding the carbohydrate metabolism status (CHMS) displayed.

Methods: Stool samples were collected from type II-III obese subjects to perform metagenomic analysis of the intestinal bacterial community. This analysis was realized by the Sequencing and Bioinformatics Service of the Foundation for the Promotion of Health and Biomedical Research of Valencia Region, according to their own protocol. To compare the differences in the relative abundance (RA) of taxa between groups, we employed SPSS v22 and performed the Wilcoxon rank sum test.

Results: Stool samples were obtained from 56 obese subjects (64% women) of 48.1(±9.8) years old and BMI 45.6(±6.6) kg/m². 22 subjects presented a normal CHMS, 15 had prediabetes and 19 suffered diabetes mellitus (DM). When comparing the microbiota composition regarding the CHMS, no differences were found in the Shannon nor Chao1 alpha-diversity indexes. At phylum level, no differences were detected either in the RA of Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria nor Verrrucomicrobia. At genus level, subjects with a normal CHMS presented higher RA of Faecalibacterium (p=0.032) and Clostridium (p=0.026) and lower of Escherichia (p=0.038), with no differences in Akkermansia. Among DM patients, 15 were treated with a GLP-1 agonist (GLP-1A): compared to the rest of the participants, these subjects displayed higher RA of the phylum Proteobacteria (p=0.044), higher RA of the genera Parabacteroides (p=0.034) and Escherichia (p=0.002), and lower RA of Clostridium(p=0.007). In the DM subgroup, patients treated with GLP-1A displayed higher RA of Bacteroides spp. (p=0.027) and lower of Prevotella spp. (p=0.009) than the rest of diabetic subjects.

Conclusions: In this small study performed in severely obese subjects, significant differences were found in the RA of the genera Faecalibacterium, Clostridium, Escherichia, Bacteroides and Prevotella in regards of the CHMS and the use of GLP-1A. Further research is needed to ascertain whether a pathophysiological relationship between these phenomena exists.