Maternal Gut Microbiome Composition and Its Potential Link to Preterm Births

Recent research suggests that the composition of the maternal gut microbiome during early pregnancy may influence the risk of preterm birth. A study published in the journal Cell Host & Microbe on September 10, 2025, identified specific bacteria associated with increased preterm birth risk. Notably, the bacterium Clostridium innocuum (C. innocuum) was found to harbor a gene capable of degrading estradiol, a crucial hormone in pregnancy.

Preterm birth remains a leading cause of infant mortality worldwide, making it vital to understand underlying factors. The researchers analyzed stool samples from two large Chinese cohorts—the Tongji-Huaxi-Shuangliu Birth Cohort and the Westlake Precision Birth Cohort—and collected blood samples to assess genetic and hormonal variations. They established a comprehensive database linking gut microbial profiles with pregnancy outcomes.

Using advanced statistical models, the team identified eleven microbial genera and one species significantly associated with preterm birth. The strongest correlation was with C. innocuum, a small, rod-shaped bacteria that produces an enzyme capable of degrading estradiol. Since estradiol is essential for maintaining pregnancy and initiating labor, dysregulation caused by C. innocuum might contribute to the onset of preterm birth.

This discovery highlights a novel aspect of the complex host-microbiome interaction during pregnancy. The researchers emphasize that monitoring gut microbiome features could become a useful approach to predicting and possibly preventing preterm births in the future. However, given that the study was conducted in Chinese populations with relatively low preterm birth prevalence, further research is necessary to determine if these findings are applicable globally.

Future efforts aim to understand the molecular mechanisms by which C. innocuum influences estrogen levels and to develop interventions that could mitigate its impact. Overall, this study underscores the importance of the gut microbiome in pregnancy health and outcomes, offering new avenues for research and potential clinical applications.

Source: https://medicalxpress.com/news/2025-09-maternal-gut-microbiome-composition-linked.html