A study from the University of Oulu and Oulu University Hospital suggests on June 15 that factors related to maternal weight are reflected in signaling particles produced by the maternal microbiota, not only in the gut but also in amniotic fluid. The findings indicate that microbiota effects may extend into the fetal developmental environment, an area where little is currently known about influencing factors.
Researchers analyzed stool and amniotic fluid samples from 60 pregnant women to investigate how maternal factors during pregnancy affect small particles produced by the body’s microbiota, known as extracellular vesicles. These vesicles are released by bacteria and enable microbes to communicate with each other while influencing host cells.
The study found that profiles of microbiota-derived vesicles in both gut and amniotic fluid varied between mothers. Maternal overweight, obesity, gestational diabetes, and weight gain exceeding 15 kilograms during pregnancy were associated with changes in these vesicle profiles—particularly within amniotic fluid. In affected mothers, certain bacterial groups produced a lower proportion of these vesicles compared to other participants.
Previous research has shown associations between maternal weight and microbiota composition during pregnancy. Historically, it was believed that fetuses developed in a sterile environment; however, this new study is among the first to examine interactions between microbiota-derived vesicles and pregnancy-related factors, with particular attention on the fetal environment.
Turunen said, “In the future, microbiota-derived vesicles could serve as biomarkers of maternal and fetal health, for example. However, before any clinical applications can be considered, we need a better understanding of the functions of these vesicles in the body. Our research group is already carrying out further studies to investigate these questions.”
