Gut Microbiota Shift in Obese Adolescents Born by Cesarean Section

Abstract

Background: It is known that in the early postnatal period a variety of factors affect the gut microbiota (GM) composition, including delivery mode. The effect of delivery mode on the human GM in the late postnatal period remains unexplored. A shift of GM composition due to delivery mode may contribute to the development of obesity in adulthood. Methods and Results: The study included six adolescents aged between 11 and 17 years treated and examined at the Clinic of the Scientific Center for Family Health and Human Reproduction (Irkutsk, Russia) in 2016. Stool samples were collected following the standard operating procedures according to the International Human Microbiome Standards. Metasequencing of V3-V4 variable regions of the 16S rRNA gene was performed by the Novogene Company (China) on the Illumina platform. Bioinformatic analysis was done by the bri-shur.com services. Sequencing reads were presented as normalized values. In general, the GM composition of obese adolescents born by cesarean section was characterized by composition heterogeneity within the Bacteroidetes phylum and the dominance of certain phylotypes as signs of dysbiosis for each adolescent. We detected an increased abundance of phyla Bacteroides and Proteobacteria, and an absence of Tenericutes in obese adolescents born by Caesarean section. On the level of genera, the prevalence of Bacteroides and Bacteroides S24-7 phylotypes, and the absence of the RF39 phylotype, led to the GM shift associated with a cesarean section or obesity. Conclusion: Obese adolescents born by cesarean section delivery present the shift in GM composition.