Dysbiosis in the Gut Microbiota of Adolescents with Obesity

Gut microbiota plays a fundamental role in the pathogenesis of metabolic disorders, including obesity. Gut microbial dysbiosis induces immune and metabolic disturbances. We wanted to find out a gut microbiota composition at adolescents with obesity and normal weight. The examined group included 40 adolescents. There were 18 obese adolescents with SDS BMI=2.77±0.55 (OB), and 22 adolescents with SDS BMI=0.01±0.50 (CO). The metagenome sequencing of V3-V4 variable regions of 16S rDNA was done by Novogene Company (China). Data were analyzed using the StatSoft STATISTICA 6.0 software package. Statistical significance was accepted at the p<; 0.05 level. Microbial richness indices and biodiversity indices were similar in the groups with obesity and normal weight. No difference was found between two groups in the phyla Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria, and in the following genera Bacteroides, Alistipes, Subdoligranulum, Megasphaera, Blautia, Akkermansia, Odoribacter, Faecalibacterium, Lactobacillus, Bifidobacterium, and Streptococcus. As well as, P/A ratio along with B/F was comparable in both groups. Nevertheless, it should be noted that significant differences in the gut microbiota composition were found for several phylotypes. The obese participants had a 2-fold decrease in Enterobacter (42 (13-61) in OB, 167 (42371) in CO, p=0.02), and an increase - in the Anaerotruncus phylotype (326 (215-732) in OB, 226 (165-320) in CO, p=0.04). Summing up, results point to the dysbiosis of the gut microbiota in adolescences with obesity due to a prevalence of bacterial groups belonging to the Anaerotruncus phylotype (the phylum Firmicutes). In contrast, the Enterobacter phylotype (the phylum Proteobacteria) is underrepresented.