AUTHOR=Ma Ting , Wu Zeyu , Lin Jing , Shan Chao , Abasijiang Aisaiti , Zhao Jin 

TITLE=Characterization of the oral and gut microbiome in children with obesity aged 3 to 5 years

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=Volume 13 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2023.1102650

DOI=10.3389/fcimb.2023.1102650

ISSN=2235-2988

ABSTRACT=Obesity has emerged in recent times as one of the major epidemics. The relationship between obesity and gut bacterial microbiota has been vastly studied. The oral cavity, as the gateway to the gut, contains the greatest number of bacteria and, together with the gut, forms a complex oral-gut cross-talk microbiome, but little is known about its impact on obesity in early childhood. Children with obesity had higher oral microbial richness but their gut microbial diversity was the lowest (Chao1: P<0.001; Observed species: P<0.001; Shannon: P<0.001). Principal coordinate analysis (PCoA) and nonmetric multidimensional scaling (NMDS) revealed significant differences in oral and gut microbial community structure between the obese group and controls. The abundance ratio of F/B in the oral and intestinal flora of obese children is higher than that of healthy children. Firmicutes, Proteobacteria, and Bacteroidetes were the three most abundant phyla in the oral and intestinal flora, accounting for more than 90%. The salivary and fecal microbial composition of genera included but was not limited to Neisseria, Bacteroides, Faecalibacterium, Streptococcus, Prevotella, Haemophilus, Veillonella, Blautia, Leptotrichia, Porphyromonas. We also identified the dominant bacterial and reliable biomarkers at phylum, family, genus, and species levels in different groups using Linear discriminant analysis effect size (LEfSe). The results of LEfSe at the genus level showed that the oral microbiota of the obese group had higher proportions of Filifactor (LDA=3,98; P<0.05) and Butyrivibrio (LDA=2.54; P<0.001) while Alloprevotella (LDA=2.95; P<0.001) were significantly more abundant in the healthy group. The fecal microbiota of children in the obese group was more enriched in Faecalibacterium (LDA=5.02; P <0.001) and Tyzzerella (LDA=3.25; P<0.01), Klebsiella (LDA=4.31; P<0.05), Citrobacter (LDA=3.94; P<0.01) were significantly more abundant in gut of healthy children. A total of 148 functional pathways of bacterial communities significantly differed between oral and gut in healthy and obese children using PICRUSt2. The presence of high-abundance microbiota in the oral and gut of children with obesity changed the state of microbes which may be a risk factor that brings potential disease risks. In addition, this study provides a theoretical basis for the etiology of childhood obesity.