Gut microbiome profiling in adolescent and adult obese patients: age-dependent differential patterns

Background & aims. Obesity has suffered of a dramatic increase over the last decades especially in childhood. In recent years, several experimental and clinical studies have provided the evidences of the involvement of gut microbiota in obesity. Particularly, gut bacteria has shown to play a critical role in the regulation of host energy metabolism and body mass . The aim of this study was to investigate the composition of the gut microbiota in obese adolescents and adults compared to age matched healthy volunteers to identify age-related microbiota profiles correlated with obesity.Methods. A group of 25 adolescent and 20 adult obese patients were analyzed for gut microbiota composition by 16S rRNA targeted metagenomics and compared to 12 adolescents and 12 adult normal weight healthy volunteers (control group). The a- and ß-diversity was evaluated, and univariate, multivariate and correlation analysis were performed on bacterial taxa profiles.Results. By a- and ß-diversity analysis showed ecological dissimilarity among the 4 study groups. At phylum level, comparison between obese versus normal weight adolescents revealed differences in Actinobacteria, Bacteroidetes and Firmicutes abundances, while, comparing adolescent versus adult obese, Actinobacteria and Bacteroidetes proportions resulted different.Conclusions. The present study revealed unique features of gut microbiome in ecological diversity, composition and OTUs correlation patterns in obese adolescent, in comparison to normal weight healthy adolescents, but also in obese and normal weight healthy adults. The assessment of possible biomarkers in microbiota profiling could lead in developing tailored-obesity treatments as new probiotic drugs. The futures investigation of probiotics for obese adolescent should consider the different microbiota profiles strictly age-related.