Association of gut microbiota and glucose metabolism in children with disparate degrees of adiposity

ObjectiveTo investigate the characteristics of gut microbiota in children with disparate degrees of adiposity, and analyze the association between gut microbiota, glucose metabolism indicators, and inflammatory factors. MethodsClinical data were examined in 89 Chinese children. Children with a body fat percentage >= 30% were diagnosed as obese, and >= 35% in males and >= 40% in females were further defined as severe obesity. The composition of gut microbiota was determined by 16S rDNA-based metagenomics. ResultsThe study population (9.75 +/- 1.92-year-old) was characterized as normal weight (n = 29), mild obesity (n = 27) and severe obesity (n = 33) groups. Linear discriminant analysis Effect Size (LEfSe) analysis found that compared to the severe obesity group, subjects with mild obesity had more prevalent members of the phylum Fusobacteria, the genus Alistipes, and fewer members of genus Granulicatella and Clostridium (p < 0.05). For subjects with mild obesity, Spearman's correlation analysis revealed that fasting plasma glucose positively correlated with species A. indistinctus, A. putredinis, and negatively correlated with species Ruminococcus gnavus; LBP negatively correlated with species Clostridium hathewayi, and Blautia producta. For subjects with severe obesity, oral glucose tolerance test 2 h plasma glucose (OGTT2HPG) negatively correlated with the phylum Synergistetes, genus Pyramidobacter, species Veillonella parvula, P. piscolens, and positively correlated with species B. producta, INS and HOMA-IR negatively correlated with the genus Haemophilus, species H. parainfluenzae, lipopolysaccharide-binding protein (LBP) negatively correlated with the phylum Actinobacteria, genus Bifidobacterium, Lactobacillus, and species B. longum (all p < 0.05). Phylogenetic investigation of communities by reconstruction of unobserved states 2 (PICRUSt2) analysis discerned that the glucose metabolism pathway, gluconeogenesis I was curtailed in the severe obesity group. ConclusionThe gut microbiota could favourably compensate for glucose metabolism in children with obesity. Genus Haemophilus and Bifidobacterium longum may influence glucose tolerance and insulin resistance in children with severe obesity.