Influence of feeding type on gut microbiome in children and adolescents

Objective. To describe the features of the taxonomic composition and alpha diversity of the gut microbiota in children and adolescents suffering from exogenous constitutional obesity and to establish the effect of the feeding type in the first year of life on these parameters. Patients and methods. This prospective single-stage study enrolled 188 children and adolescents aged 13.1 ± 4.1 (10–18) years, including healthy volunteers (n = 96) and patients with exogenous obesity (n = 92). A metagenomic analysis of gut microbial communities depending on the type of feeding in the first year of life was performed. The study of DNA extracted from stool samples was carried out by 16S rRNA gene sequencing (V3–V4 regions). Results. In the gut microbiome of obese children as compared with healthy ones, there was a statistically significant decrease in the content of Bacteroidetes phylum (35.36% vs 39.44%) and Proteobacteria (1.99% vs 2.53%) and an increase in the Firmicutes phylum (53.95% vs 49.29%) and alpha diversity indices (p < 0,05 for Chao1, Shannon, Simpson indices, number of OTUs). Healthy children who were fed artificially during their first year of life showed a statistically significant decrease in diversity indices of the gut microbiota in comparison with breastfed children. Conclusion. The results obtained indicate the importance of the feeding type over the first year of life in the development of the gut microbial diversity and indicate the long-term maintenance of the effect of this factor up to adolescence. Key words: obesity, gut microbiota, Bacteroidetes, Firmicutes, breastfeeding, 16S rRNA