Study On The Association Between Air Pollutants And Gut Microbiota With Postpartum Depression

ObjectiveAir pollutant exposure and gut microbiota can affect the occurrence of depression,but the association between air pollutants and gut microbiota and postpartum depression（PPD）is still unclear.This study analyzed the association between air pollutants and gut microbiota and PPD,and clarified the sensitive window of exposure to air pollutants during pregnancy and the gut microbiota associated with PPD during pregnancy,in order to provide a scientific basis for reducing the risk of PPD by improving the degree of air pollution and the composition of gut microbiota.MethodsThis was a prospective cohort study.The research subjects came from the dynamic prospective cohort of metabolic diseases of pregnancy and adverse pregnancy outcomes（PMDAPO）established in Guangzhou Women and Children’s Medical Center by the research group.The first prenatal check-up of pregnant women was used as the starting point of the study cohort,and the first check-up information was used as the baseline data.All the subjects were followed up to 42 days postpartum.Part Ⅰ:Epidemic status of postpartum depression and its association with air pollutants2742 pregnant women enrolled in the PMDAPO cohort from July 2016 to December2017 were selected as the study subjects.At 6 weeks postpartum,data on social support of the subjects were collected,and the Edinburgh Postpartum Depression Scale（EPDS）was used to investigate the incidence of PPD.The data of air pollutant came from the national urban air quality real-time release platform.The air pollutant data from the air quality monitoring station nearest to the subject’s usual residence during pregnancy was used for individual exposure assessment.Using the logistic regression to analyze the association between air pollutant exposure and PPD in different gestational Windows.Part Ⅱ:Correlation analysis of gut microbiota and postpartum depression during pregnancy345 pregnant women enrolled in the PMDAPO cohort from July 2016 to December2017 were selected as the study subjects.Stool samples of the subjects were collected in the second or third trimester,and the subjects were surveyed with the Edinburgh Postpartum Depression Scale at 6 weeks postpartum.The DNA in the stool sample was extracted,and the 16S r RNA V4 region was amplified by PCR.The Illumina Mini Seq sequencing platform was used for sequencing,and the QIIME2 software was used for subsequent analysis.Using the linear discriminant analysis（LDA）effect size（LEf Se）method to identify bacterial abundance between the PPD and control groups.Spearman correlation analysis was used to analyze the association between EPDS score,air pollutants and gut microbiota.ResultsPart Ⅰ:Epidemic status of postpartum depression and its correlation with air pollutants1.A total of 2742 women were included in this study,including 2390 non-PPD women and 352 PPD patients.The incidence of PPD was 12.84%.2.Univariate analysis of the influencing factors of PPD showed that PPD group and healthy control group had significant differences in age,pre-pregnancy BMI,adverse pregnancy history,gravidity,parity,newborn weight,family relationship,friend relationship,contact frequency with friends,life satisfaction and sleep quality（P<0.05）.3.Logistic multivariate analysis of the influencing factors of PPD showed that advanced age was a protective factor for PPD,while poor family relationships,lack of contact with friends,poor sleep quality and low life satisfaction were risk factors for PPD（P<0.05）.4.Logistic regression models of single pollutant,double pollutant and multi-pollutant all showed that O₃ was positively correlated with PPD,but the difference was not statistically significant（P>0.05）.The results of the single-pollutant linear regression model showed that O₃ exposure during the whole pregnancy was positively correlated with EPDS score（β=0.364,95%CI:0.036-0.693）.After adjusting for SO₂,the association between O₃ and EPDS score was still significant（β=0.354,95%CI:0.025-0.682）.The multi-pollutant model showed that the first trimester is the susceptibility window for PM_2.5 to have adverse effects on PPD.After adjusting for SO₂ and NO₂,for every 10μg/m³ increase in PM_2.5 exposure in the first trimester,the risk of PPD increased by 1.681 times（95%CI:1.152-2.445）.Exposure to SO₂ and NO₂ during pregnancy was not significantly associated with PPD.Part Ⅱ:Correlation analysis of gut microbiota during pregnancy and postpartum depression1.There was no significant difference in the alpha diversity andβdiversity of the gut microbiota between the PPD group and the control group during pregnancy.2.The gut microbiota of PPD group and the control group were different in the second and third trimesters.At the family level,the abundances of[Paraprevotellaceae]and[Mogibacteriaceae]increased in the second trimester of the PPD group,while the abundances of Clostridiaceae and Lachnospiraceae decreased;the abundance of Pasteurellaceae increased in the third trimester of the PPD group,while Fusobacteriaceae and[Mogibacteriaceae].At the genus level,the abundances of Enterococcus,Curtobacterium,Abiotrophia and Paraeggerthella increased in the second trimester of the PPD group,while the abundances of Megasphaera and Clostridium decreased;the abundance of Moryella,Raphanus,Plesiomonas,and Haemophilus increased in the third trimester of the PPD group,while the abundance of Synergistes and[Ruminococcus]decreased.3.NO₂ and O₃ exposure were positively correlated with Megasphaera and Lachnospiraceae（P<0.05）.Conclusions1.Poor social support and sleep quality were risk factors for PPD.2.The first trimester may be the susceptibility window for PM_2.5 to have adverse effects on PPD.Exposure to O₃ during pregnancy was positively associated with EPDS,suggesting that O₃ may be a potential risk factor for PPD.3.The decrease of anti-inflammatory bacteria（Lachnospiraceae,Fusobacteriaceae,Clostridium and Megasphaera）and the increase of opportunistic pathogens（Pasteurellaceae,Enterococcus,Abiotrophia,Paraeggerthella,Moryella and Plesiomonas）in pregnant women during pregnancy would increase the risk of PPD.