Abstract：
The infant gut microbiome matures greatly in the first year of life. Ambient air pollution (AAP) exposure is associated with the infant gut microbiome. However, whether time-varying AAP influences infant gut microbiome variation is rarely investigated. This study aimed to investigate the effects of PM2.5, PM10, and O3 on infant gut microbiome variation longitudinally. Demographic information, stool samples, and AAP exposure concentrations were collected at 6, 12, 24 months from infants. Gut microbiome was processed and analyzed using 16S rRNA V3-V4 gene regions. AAP exposure concentrations were calculated using the China High Air Pollutants (CHAP) database. Multiple pollutant models were used to assess the mixed effects of PM2.5, PM10, and O3 on infant gut microbiome variation. Infants\' gut microbiomes at 6, 12, 24 months old had significant differences in alpha diversity, beta diversity, and community composition. PM2.5 and O3 respectively explained 6.3% and 5.3% of the differences in community composition for 24-month-old infants. Single pollutant exposure and multiple pollutant exposure in different periods were both associated with alpha diversity indices and specific gut microbial phyla and genera. AAP was more associated with infant gut microbial alpha diversity indices, phyla variations, and genera variations at 12-24 months than 6-12 months. Multiple pollutant exposure in 0-2 lag months showed negative correlations with 12-24 months variation in Escherichia-Shigella (β = -0.854, 95%CI: 1.398 to -0.310) and Enterococcus (β = -0.979, 95%CI: 1.429 to -0.530). This study highlighted that time-varying PM2.5, PM10, and O3 synergistically influenced the variation of alpha diversity and abundance of gut microbial taxa in infants. Further research is needed to explore the effects and mechanisms of other environmental exposures on infant gut microbiome variation.
摘要：
婴儿肠道微生物组在生命的第一年就大大成熟。环境空气污染（AAP）暴露与婴儿肠道微生物组有关。然而,随时间变化的AAP是否会影响婴儿肠道微生物组变化的研究很少。本研究旨在纵向研究PM2.5、PM10和O3对婴儿肠道微生物组变化的影响。人口统计信息,粪便样本,和AAP暴露浓度在6,12,24个月的婴儿收集。使用16SrRNAV3-V4基因区处理和分析肠道微生物组。使用中国高空气污染物（CHAP）数据库计算AAP暴露浓度。使用多种污染物模型来评估PM2.5，PM10和O3对婴儿肠道微生物组变化的混合影响。6、12、24个月大的婴儿肠道微生物在α多样性上有显著差异，β多样性,和社区组成。PM2.5和O3分别解释了24个月婴儿社区组成差异的6.3％和5.3％。不同时期的单污染物暴露和多污染物暴露均与α多样性指数和特定的肠道微生物门和属有关。AAP与婴儿肠道微生物α多样性指数更相关，门变异，和属的变化在12-24个月比6-12个月。在0-2个月的多污染物暴露与大肠杆菌-志贺菌（β=-0.854，95CI：-1.398至-0.310）和肠球菌（β=-0.979，95CI：-1.429至-0.530）的12-24个月变异呈负相关。这项研究强调，随时间变化的PM2.5，PM10和O3协同影响婴儿肠道微生物分类群的α多样性和丰度的变化。需要进一步的研究来探索其他环境暴露对婴儿肠道微生物组变异的影响和机制。
