Study On Intestinal Microbiota In Patients With Kawasaki Disease Based On High Throughput Sequencing

【Objective】The aim of this study was to investigate the gut microbial dysbiosis in children with Kawasaki disease.The richness,diversity,composition and characteristics of intestinal microbiota were analyzed to explore the potential correlation between Kawasaki disease and intestinal microbiota.【Methods】A total of 61 children were enrolled in this study,including 26 children with Kawasaki disease who were hospitalized in Jinan Children’s Hospital during August 2017 to March 2018 and 35 healthy children who passed the medical examination in the hospital during the same period.The V1~V2 variable region in 16 S rRNA gene was amplified by PCR from fecal samples collected from affected with Kawasaki disease and matched healthy children,and analyzed for bacterial taxonomic content following high-throughput sequencing.Microbiota in affected and healthy children were compared by alpha diversity,beta diversity,linear discriminant analysis and LDA effect size analysis.【Results】Chi square test showed no significant difference in sex ratio between the two groups(P= 0.237).The mean age of Kawasaki disease group(2.1 ± 1.96y)was similar with that of healthy control group(2.0 ± 2.1y)(P = 0.574).The results of alpha diversity analysis showed that the Shannon index and Ace index of intestinal microbiota in Kawasaki disease group were higher than those in healthy control group,but only the latter had statistical significance(P<0.0001).The results of PCoA(UniFrac,Unweighted)showed that the intestinal microbial structure of Kawasaki disease patients was significantly different from that of healthy controls.ANOSIM analysis showed that the difference of intestinal microbial structure between the two groups was statistically significant(P<0.01).After clustering analysis of OTUs,it was found that there were three main phylums in both groups: Firmicutes,Bacteroides and Proteobacteria.The results of genus-level analysis showed that the main Kawasaki disease components(with an average content of more than 1%)included Bacteroides,Lactobacillus,Veillonella,Faecalibacterium,Enterococcus,Parabacteroides,Photobacterium,Bifidobacterium,Streptococcus and Sutterella.The main members of the control group(with an average content of more than 1%)included Bacteroides,Lactobacillus,Veillonella,Faecalibacterium,Clostridium,Streptococcus and Sutterella.We used LEfSe to analyze the difference of intestinal microbial composition.The results showed that the phylum of Bacteroidetes and Actinobacteria increased in the Kawasaki disease group(LDA>3.0).At the generic level,genus of Bacteroides,Enterococcus,Faecalibacterium,Photobacterium,Parabacteroides,Bifidobacterium and Sutterella also increased significantly(LDA>3.0).In the healthy group,the target microorganisms increased in Firmicutes,Lactobacillus,Veillonella,Clostridium and Epulopiscium at the generic level(LDA>3.0).【Conclusions】(1)The results of this study indicated that there was a disorder of intestinal microbiota in children with Kawasaki disease.(2)Compared with healthy children,the richness of intestinal microbiota in children with Kawasaki disease had increased,and the composition and structure had also changed,which might be related to the etiology or pathogenesis of Kawasaki disease.(3)The results of this study provide some theoretical basis for the prevention or diagnosis of Kawasaki disease based on intestinal microecology.