Gut microbiota associated with obesity and high carotid intima-media thickness among Chinese children

Abstract Background High carotid intima-media thickness (cIMT) in childhood, usually combined with obesity, is an early predictor of cardiovascular disease (CVD) later in life. However, the association between gut microbiota and high cIMT among children with obesity remains unclear. Therefore, we compared differences in composition, community diversity, and richness of gut microbiota among children with obesity and high cIMT (OB + high-cIMT), obesity but normal cIMT (OB + non-cIMT), and normal weight and normal cIMT (i.e., normal children) to identify differential microbiota biomarkers. Methods A total of 24 OB + high-cIMT children, 24 OB + non-cIMT children, and 24 normal children aged 10–11 years from the Huantai Childhood Cardiovascular Health Cohort Study were included. All included fecal samples were tested using 16S rRNA sequencing. α-diversity analysis was performed to estimate the community richness and diversity of gut microbes, and LEfSe analysis was used to reveal the main differential biomarkers among these three groups. Random forest analysis was used to further select differential biomarkers. The receiver operating characteristic (ROC) curve was used to evaluate the ability of biomarkers in identifying OB + non-cIMT and OB + high-cIMT. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were assessed by Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) according to the KEGG database. Results The community richness and diversity of gut microbiota in OB + high-cIMT children were decreased compared with OB + non-cIMT children and normal children. At the genus level, the relative abundances of Christensenellaceae_R-7_group, UBA1819, Family_XIII_AD3011_group, and unclassified_o__Bacteroidales were reduced in OB + high-cIMT children compared with OB + non-cIMT and normal children. In addition, these four significant biomarkers were ranked in the top 1, 2, 6, and 12 in the random forest analysis. ROC analysis results showed that combined Christensenellaceae_R-7_group, UBA1819, Family_XIII_AD3011_group, and unclassified_o__Bacteroidales performed high ability in identifying OB + high-cIMT (area under the curve [AUC]: 0.91, 95% CI = 0.82–1.00]) and moderate ability in identifying OB + non-cIMT (AUC 0.76, 95% CI = 0.62–0.91). PICRUSt showed unique thiamine metabolism and methane metabolism pathways in gut microbial were decreased in OB + high-cIMT compared with OB + non-cIMT. Conclusion Gut microbiota plays a pivotal role in detecting children with obesity combined with high cIMT.