脐血有机磷阻燃剂暴露与新生儿胎粪菌群的关联研究

Association between umbilical blood organophosphate esters exposure and meconium microbiome of newborns

[背景]动物实验研究显示,有机磷阻燃剂(OPEs)暴露与小鼠、斑马鱼的肠道菌群系统紊乱相关,人群证据较少。鉴于肠道菌群对新生儿发育的重要作用,探讨OPEs暴露对新生儿发育早期菌群的潜在影响显得尤为重要。[目的]探索脐血OPEs暴露对新生儿胎粪菌群多样性及组成的影响。[方法]本研究依托上海亲子队列,纳入391名具备完整随访信息和生物样本的孕妇及其子代。使用超高效液相色谱-串联质谱法检测新生儿脐带血中OPEs质量浓度(后称浓度)。在新生儿分娩后收集胎粪,使用Illumina Miseq测序平台进行16S r RNA测序分析。应用多重线性回归模型评估OPEs暴露对新生儿肠道菌群α多样性的影响。通过非加权Uni Frac距离的主坐标分析和置换多元方差分析比较不同类型OPEs高、低暴露组间菌群β多样性的差异。采用线性判别分析效应大小(LEfSe)分析不同OPEs高、低暴露组间差异肠道菌群类群。基于京都基因和基因组百科全书(KEGG)数据库预测胎粪菌群功能通路,并使用多变量线性回归模型(MaAsLin2)探索OPEs暴露对肠道菌群通路的影响。[结果]新生儿脐血样本中共检出7种OPEs暴露,其中磷酸三丁酯(TBP)、磷酸三(2-丁氧基乙基)酯(TBEP)、磷酸二苯异辛酯(EHDPP)和磷酸三(2-氯-1-(氯甲基)乙基)酯(TDCPP)检出率大于50%,其浓度中位数分别为0.52、2.41、0.13和2.23μg·L-1。脐血TBEP和TDCPP暴露水平与新生儿胎粪菌群α指数相关,同时OPEs高、低暴露分组的β多样性差异有统计学意义。LEfSe结果表明,脐血OPEs暴露与链球菌、棒状杆菌、奈瑟菌属、嗜血杆菌属和副拟杆菌属等27个菌属存在关联。MaAsLin2分析发现,OPEs暴露和亚油酸代谢、类固醇合成、Toll和Imd信号通路、视黄醛代谢、NOD样受体信号通路和脂肪酸合成等通路上调存在关联。[结论]脐血OPEs暴露与新生儿胎粪菌群的α多样性指数增加以及奈瑟菌属、链球菌属、副拟杆菌属和棒状杆菌属等菌属相对丰度增加存在关联,并且与亚油酸代谢和脂肪酸合成等预测的代谢通路改变存在关联,表明脐血OPEs暴露可影响胎粪菌群稳态。

[Background]Animal studies have shown that exposure to organophosphate esters(OPEs)disturbs the composition of gut microbiome in rodents and zebrafish.However,current associated evidence in humans is limited.Considering the importance of gut microbiome in neonatal development,we need to investigate the impact of OPEs exposure on the early development stage of neonatal microbiome.[Objective]To investigate the associations between umbilical OPEs exposure and the diversity and composition of gut microbiome in newborns.[Methods]Based on the Shanghai Maternal-Child Pairs Cohort(MCPC),391 mother-infant pairs with comprehensive follow-up information and bio-samples were enrolled in this study.Concentrations of OPEs in neonatal cord blood were quantified using ultra performance liquid chromatography-tandem mass spectrometry.Meconium samples were collected after delivery and measured through 16S rRNA sequencing on the Illumina Miseq platform.Multiple linear regression models were used to assess the effects of OPEs exposure on the alpha diversity of meconium microbiome.Principal coordinate analysis and permutational multivariate analysis of variance based on unweighted UniFrac distance were used to compare the beta diversity differences between high and low exposure groups of OPEs.Linear discriminant analysis effect size(LEfSe)was utilized to analyze the differential gut microbiome taxa between high and low OPEs exposure groups.The functional pathways involved in the meconium microbiome were predicted based on the Kyoto Encyclopedia of Genes and Genomes(KEGG)database,and multivariate analysis by linear models(MaAsLin2)were conducted to explore the effects of OPEs exposure on gut microbiome pathways.[Results]Seven OPEs were detectable in the neonatal cord blood samples,of which four were detected higher than 50%including tributyl phosphate(TBP),tris(2-butoxyethyl)phosphate(TBEP),2-ethylhexyl diphenyl phosphate(EHDPP),and tris(2-chloro-1(chloromethyl)ethyl)phosphate(TDCPP),and the median concentrations of these four congeners were as follows:0.52μg·L-1 for TBP,2.41μg·L-1 for TBEP,0.13μg·L-1 for EHDPP,and 2.23μg·L-1 for TDCPP.A significant association was observed between umbilical TBEP and TDCPP exposure and alpha diversity indices in neonatal meconium microbiome.Beta diversity significantly differed across varied high and low OPEs exposure groups.The results of LEfSe analysis indicated a significant correlation between umbilical OPEs exposure and 27 genera,including Streptococcus,Corynebacterium,Neisseria,Haemophilus,and Parabacteroides.The MaAsLin2 analysis identified associations between OPEs exposure and upregulation of pathways related to linoleic acid metabolism,steroid biosynthesis,Toll and Imd signaling pathway,retinol metabolism,NOD like receptor signaling pathway,and fatty acid biosynthesis.[Conclusion]Umbilical OPEs exposure is associated increased alpha diversity indices,increased relative abundances of Neisseria,Streptococcus,Parabacteroides,and Corynebacterium in the gut microbiome,as well as predicted metabolic pathway alterations in linoleic acid metabolism,fatty acid biosynthesis,etc.These findings indicate that umbilical OPEs exposure may disrupt meconium microbiome equilibrium.