Altered Gut Microbiota and Shift inBacteroidetesbetween Young Obese and Normal-Weight Korean Children: A Cross-Sectional Observational Study

Abstract

Emerging data suggest that the gut microbiome is related to the pathophysiology of obesity. This study is aimed at characterizing the gut microbiota composition between obese and normal-weight Korean children aged 5-13. We collected fecal samples from 22 obese and 24 normal-weight children and performed 16S rRNA gene sequencing using the Illumina MiSeq platform. The relative abundance of the phylum Bacteroidetes was lower in the obese group than in the normal-weight group and showed a significant negative correlation with BMI z-score. Linear discriminative analysis (LDA) coupled with effect size measurement (LEfSe) analysis also revealed that the Bacteroidetes population drove the divergence between the groups. There was no difference in alpha diversity, but beta diversity was significantly different between the normal-weight and obese groups. The gut microbial community was linked to BMI z-score; blood biomarkers associated with inflammation and metabolic syndrome; and dietary intakes of niacin, sodium, vitamin B6, and fat. The gut microbiota of the obese group showed more clustering of genera than that of the normal-weight group. Phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) analysis revealed that the functions related to carbohydrate and lipid metabolism in the microbiota were more enriched in the normal-weight group than in the obese group. Our data may contribute to the understanding of the gut microbial structure of young Korean children in relation to obesity. These findings suggest that Bacteroidetes may be a potential therapeutic target in pediatric obesity.

Lifestyle modifications result in alterations in the gut microbiota in obese children

“…In the baseline analysis, the obese children in the fat gain group showed decreased proportions of Bacteroidetes compared with the controls, as described by previous studies [ 15 , 18 , 27 , 28 ]. The gut microbiota in the obese children showed a different microbial composition from that in the controls, including increased proportions of the genera Blautia , Dorea , Eubacterium hallii group, and Fusicatenibacter , which were reported to be associated with obesity, as well as decreased proportions of the genera Bacteroides, Oscillibacter , and Parabacteroides , which were positively associated with leanness [ 18 , 29 – 31 ]. In both the preintervention groups, reduced microbial richness was noted, and the beta diversity showed significant separation between the control and obese groups, generally implicating dysbiotic features [ 30 ].…”

“…For the baseline analysis, 16S rRNA gene sequencing data from the feces of the obese groups at the preintervention stages were compared with those of 24 normal-weight children (18 boys and 6 girls, aged 8.1 ± 1.5 years old) from our previous cross-sectional study of pediatric obesity as controls using Quantitative Insights into Microbial Ecology 2 (QIIME2) [ 18 ]. Among the results of anthropometric measurements, BMI in the obese group before intervention was significantly higher than that in the control group (Wilcoxon’s rank-sum test, P < 0.05, Table S2 ).…”

“…The taxonomy of these features was assigned via the Silva-genes reference database classifier (version 136) considering 99% similarity. 16S rRNA gene sequencing data of the preintervention stages in both groups were compared with those of 24 normal-weight children in our previous cross-sectional study of pediatric obesity as controls [ 18 ]. The differential compositional analyses of the gut microbiota between the controls and both groups in the preintervention stages were performed by STAMP software [ 19 ].…”

Adzuki Bean Alleviates Obesity and Insulin Resistance Induced by a High-Fat Diet and Modulates Gut Microbiota in Mice

“…The HFD group has a higher relative abundance of lipopolysaccharide biosynthesis, which was consistent with the high serum LPS levels, but adzuki bean treatment has a significant negative regulatory effect on the content of LPS (Figure 2C). Furthermore, cysteine and methionine metabolism is part of sulfur metabolism, which promotes the production of H 2 S [66]. H 2 S has adverse effects on the energy metabolism of the colonic epithelium, which promotes harmful intestinal substances from entering the circulatory system [67].…”

Gut Microbiota as a Mediator of Essential and Toxic Effects of Zinc in the Intestines and Other Tissues

“…In obese Korean children, zinc intake was found to be inversely associated with dietary zinc intake [ 83 ]. These findings corroborate earlier data on the beneficial role of Bacteroidetes in body weight regulation [ 84 ], thus providing an additional potential mechanism for protective effects of Zn in obesity [ 85 ].…”