Maternal weight may influence microbiota signaling in amniotic fluid
· Medical Xpressedited by Lisa Lock, reviewed by Andrew Zinin
Lisa Lock
Scientific Editor
Meet our editorial team
Behind our editorial process
Andrew Zinin
Lead Editor
Meet our editorial team
Behind our editorial process Editors' notes
This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility:
fact-checked
peer-reviewed publication
trusted source
proofread
The GIST Add as preferred source
A study conducted at the University of Oulu and Oulu University Hospital suggests 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 finding indicates that the effects of the microbiota may extend to the fetal developmental environment. The result is of particular interest because little is currently known about the factors that influence microbiota signaling within the fetal environment.
The researchers analyzed stool and amniotic fluid samples from 60 pregnant women. They investigated how maternal factors during pregnancy affect small particles produced by the body's microbiota, known as extracellular vesicles. These are signaling particles released by bacteria that enable microbes to communicate with one another and influence the host's cells.
"Microbiota-derived vesicles are likely one of the most important communication mechanisms between the microbes in our bodies and our cells. The fetal environment refers to the conditions surrounding the fetus in the womb, including the amniotic fluid. Microbiota signaling within the fetal environment, and changes in that signaling, may have a significant impact on the development of the fetal immune system, for example," says Jenni Turunen, postdoctoral researcher at the University of Oulu.
The researchers found that the profile of microbiota-derived vesicles in both the gut and amniotic fluid varied between mothers. Maternal overweight, obesity, gestational diabetes and weight gain of more than 15 kilograms (33 pounds) during pregnancy were associated with microbiota-derived vesicle profiles, particularly in amniotic fluid. In these mothers, the proportion of vesicles produced by certain bacterial groups was lower than in the other study participants. The results are published in the journal BMC Medicine.
Previous studies have identified associations between maternal weight and the composition of the microbiota during pregnancy. In addition, the fetus was long thought to develop in a sterile environment. The newly published study is among the first to examine the interaction between microbiota-derived vesicles and pregnancy-related factors, with a particular focus on the fetal environment.
According to Turunen, microbiota-derived vesicles could offer new opportunities for monitoring health during pregnancy.
"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," Turunen says.
Publication details
Jenni Turunen et al, Maternal factors associate with microbiota-derived extracellular vesicle profiles in pregnancy: a clinical cohort study, BMC Medicine (2026). DOI: 10.1186/s12916-026-04960-3
Journal information: BMC Medicine
Key medical concepts
Extracellular VesiclesAmniotic FluidmicrobiotaBiomarkersDiabetes and Pregnancy
Clinical categories
Obstetrics & gynecologyPregnancy Provided by University of Oulu Who's behind this story?
Lisa Lock
BA art history, MA material culture. Former museum editor, paramedic, and transplant coordinator. Editing for Science X since 2021. Full profile →
Andrew Zinin
Master's in physics with research experience. Long-time science news enthusiast. Plays key role in Science X's editorial success. Full profile →
Citation: Maternal weight may influence microbiota signaling in amniotic fluid (2026, June 21) retrieved 21 June 2026 from https://medicalxpress.com/news/2026-06-maternal-weight-microbiota-amniotic-fluid.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.