学龄儿童肥胖与肠道菌群多样性及菌属丰度的关联研究

目的分析学龄肥胖儿童和正常体重儿童肠道菌群多样性差异, 识别肥胖儿童肠道特征菌属, 为后续相关机制研究和学龄儿童肥胖的防治提供依据。方法基于2016年在上海市嘉定区某小学建立的研究队列人群, 将2016-2018年3年均处肥胖状态的儿童共63名纳入肥胖组, 其中男生43名, 女生20名。在3年均为正常体重的儿童中, 根据年龄、性别和所在班级, 将其与肥胖组儿童进行1∶1匹配, 共选择63名纳入对照组。采用问卷收集儿童基本信息、饮食状况、母乳喂养等情况, 收集两组儿童的粪便样本并进行16S rDNA测序。对质量优化后的测序序列按照97%相似性进行可操作分类单元聚类及物种注释。分析肥胖组和对照组儿童肠道菌群多样性及菌属丰度差异。计算肠道菌群的Ace、Chao1、Shannon、Simpson 4种α多样性指数, 并利用主坐标分析, 在非加权Unifrac距离和加权Unifrac距离的基础上表示β多样性。使用相似性分析(ANOSIM)比较两组β多样性的差异。利用STAMP软件挑选出两组儿童共有菌属中的差异细菌, 并利用广义线性模型(GLM)分析肥胖与α多样性以及显著差异菌属的关联。结果肥胖组...

Association between obesity with the diversity and genus of gut microbiota in school-aged children

Objective To analyze the diversity differences of gut microbiota between school-aged obese children and normal-weight children and identify the characteristic flora in obese children to provide some evidence for the subsequent study of the following study-related mechanisms and the prevention and treatment of obesity in school-aged children.Methods This study was based on a cohort established in a primary school in Jiading district,Shanghai,2016.Sixty-three children,including 43 boys and 20 girls,who were obese during the three years from 2016 to 2018,were enrolled in the obesity group.Among children who were average weight for three years,a total of 63 were selected as the control group,with matching with the obese ones in a 1 to 1 way according to age,sex and class.The primary characteristics,diet status,breastfeeding,and other information of children were collected by questionnaire.Fecal samples of participants in both groups were collected,and 16S rDNA sequencing was performed.Operable taxon units clustering according to 97%similarity and species annotation were based on the quality-optimized sequences.The difference in the diversity and genius of gut microbiota among children in the obesity and control groups were analyzed.Theαdiversity indices,including Ace,Chao1,Shannon,and Simpson index,were calculated.Theβdiversity was presented based on unweighted Unifrac distance and weighted Unifrac space by principal coordinate analysis.The differences inβdiversity between the two groups were compared by similarity analysis(ANOSIM).The differences in genus distribution between the two groups were selected by STAMP software.The association of obesity with theαdiversity and genus with significant differences were analyzed by the generalized linear model(GLM).Results The Ace and Chao1 index in the obesity group was significantly lower than those in the control group(The P values were 0.026 and 0.039,respectively).There was no significant difference in Shannon and Simpson index between the two groups(The P values were 0.879 and 0.922,respectively).The results of ANOSIM showed differences in gut microbiota between the two groups(R>0),but the group contribution was not significant(unweighted Unifrac distance:R=0.006,P=0.223;weighted Unifrac distance:R=0.010,P=0.134).Among the obese group,the relative abundance of Prevotella and Sarcina was highest in the endemic genus.The STAMP results showed that the relative lots of 15 genera were significantly different between the two groups(P<0.05).The results of GLM showed that,compared with the control group,the obesity group had a lower level of the relative abundance in Akkermansia muciniphila,while a higher level in Coprococcus_3,Ruminococcus,Agathobacter and Collinsella.After stratification by sex,the Chao1 index was also lower in the obese boys than that in the normal-weight boys.However,the obese girls only had a higher level in Coprococcus_3 than the ordinary weight girls.Conclusions Compared with children with average weight,obese children had lowerαdiversity of gut microbiota and lower relative abundance of dominant probiotics but had a higher relative lot of genus associated with metabolic disorders,inflammation promotion,and metabolism rate reduction.