川崎病儿童肠道菌群多样性及差异性与免疫功能的关系研究

Relationship between intestinal flora diversity and immune function in children with Kawasaki disease

目的 探讨川崎病(KD)儿童肠道菌群多样性及差异性与免疫功能的关系。方法 选取2020年1月至2022年6月在湖州市中心医院住院的KD患儿39例及同期健康对照儿童17名为研究对象。采用ELISA法检测血清免疫细胞因子IL-2、IL-4、IL-6、IL-10、IFN-γ、TNF-α水平。使用Illumina Hiseq 2500高通量测序平台对粪便合格样本进行测序。对测序数据进行α多样性分析,包括Observed Species指数、Chao1指数、Shannon指数和Simpson指数,试图综合评价所调查样本的丰富度和均匀度。进一步做两组间β多样性分析,包括主坐标分析、主成分分析,试图找出两组儿童之间的差异。应用偏最小二乘判别分析寻找两组在物种水平上的差异。选择线性判别分析高于2.0的物种作为两组之间的潜在生物标志物。结果 KD患儿IL-2、IL-4、IL-6、IL-10、IFN-γ、TNF-α水平均高于健康对照儿童,差异均有统计学意义(均P<0.05)。韦恩图显示,KD患儿和健康对照儿童肠道菌群共同的操作分类单元(OTU)数为686个,KD患儿独有的OTU数为39个。Chao1指数显示KD患儿肠道菌群丰富度低于健康对照儿童(P<0.05),其他3个指数组间比较差异均无统计学意义(均P>0.05)。与健康对照儿童相比,KD患儿杆菌、乳酸杆菌、普氏菌、巨单胞菌和韦荣氏菌丰度均显著上调,而瘤胃球菌、李克氏菌科、阿里斯蒂佩斯菌丰度均显著下调。结论 KD患儿肠道菌群的多样性及差异性可能与免疫细胞因子水平上调有关。

Objective To explore the relationship between intestinal flora diversity and immune function in children with Kawasaki disease.Methods Thirty-nine KD patients admitted in Huzhou Central Hospital from January 2020 to June 2022and 17 matched healthy children(control group) were enrolled.Serum IL-2,IL-4,IL-6,IL-10,IFN-γ and TNF-α levels were detected by ELISA.Fecal DNA samples were sequenced using Illumina Hiseq 2500 high-throughput sequencing platform.Theα diversity analysis was performed for the data,including Observed Species,Chao1,Shannon and Simpson,and β diversity analysis was further performed,including PCoA and PCA to find differences between the KD group and the control group.Partial least squares discriminant analysis was used to examine the differences between the two groups at the species level.Species with LDA scores higher than 2.0 were selected as potential biomarkers between the two groups.Results Serum IL-2,IL-4,IL-6,IL-10,IFN-γ and TNF-α levels in KD children were significantly higher than those in control group(all P<0.05).The Venn diagram showed that the number of operational taxonomic units(OTU) in the intestinal flora of KD children and control group was 686,and the number of OTU unique to KD children was 39.Chao1 index showed that the intestinal flora richness of KD children was lower than that of control group(P<0.05),and there was no statistical significance between the other three indexes(all P>0.05).The abundance of Bacilli,Lactobacillales,Prevotella,Megamonas and Veillonella in the intestinal strains of KD patients was significantly up-regulated,while that of Ruminococcus,Rikenellaceae and Alistipes was down-regulated.Conclusion The diversity and differences of intestinal flora may be related to the up-regulated expression of inflammatory immunomodulators in KD patients.