Associations between combined healthy lifestyle and adverse birth outcomes in 2 prospective cohorts: roles of gut microbiota and serum metabolites

Maternal lifestyle factors are reported to be associated with adverse birth outcomes (ABOs). These factors may also dynamically influence gut microbiota composition and serum metabolic profiles. To investigate the associations between combined healthy lifestyle and ABOs, and the mediating roles of gut microbiota and serum metabolites. This study was conducted based on the Tongji-Huaxi-Shuangliu Birth Cohort (THSBC), comprising 1086 participants with repeated multi-omics data collected at three time points. An independent validation was performed using 161 participants from the Huaxi Birth Cohort (HBC), with available multi-omics data at five time points. Participants were classified into three lifestyle categories (unhealthy, low healthy, and highly healthy) according to diet, physical activity, smoking, drinking, sleep, and body mass index. Gut microbiota were characterized using 16S rRNA gene sequencing in the THSBC and metagenomics in the HBC, while serum metabolites were profiled using untargeted liquid chromatography-mass spectrometry. Clinical data on birth outcomes, such as gestational age, birth weight, and sex were collected in the THSBC. A highly healthy lifestyle was associated with lower risks of macrosomia (MAC) (odds ratio: 0.43; 95% confidence interval: 0.33, 0.57), preterm birth (PTB) (0.60; 0.46, 0.79), and large for gestational age (LGA) (0.44; 0.35, 0.56). Among the identified mediators, gut microbiota and serum metabolites, including Eisenbergiella, Tyzzerella, Megamonas, pro-Ile, and 1-amino-1-cyclobutane-carboxylic acid were negatively associated with a healthy lifestyle, while Lachnospiraceae NK4A136 group, 4-methoxyestrone, and LPC (0:0/18:3) were positively associated. Mediation analyses showed that Eisenbergiella and 4-methoxyestrone explained 11.4% and 13.0% of the inverse association between a highly healthy lifestyle and PTB, respectively, while the other microbiota and metabolites mediated 5%-7% of the associations with MAC and LGA. Maternal healthy lifestyle was associated with lower risks of ABOs, with gut microbiota and serum metabolites serving as important mediators in these relationships.