Imma Perfetto
Cosmos science journalist
New research in mice shows that a species of gut bacteria, Bifidobacterium breve, regulates the placental production of hormones which are critical for healthy pregnancy.
Pregnant mice without B. breve in their guts were also found to experience a higher rate of complications and increased early foetal loss.
B. breve occurs naturally in the human and mouse gut microbiome and increases in late pregnancy in both species. But stress or obesity in pregnant people can alter its abundance.
The new study is the first to show the presence of this bacterial species in the gut can influence hormone production in the placenta.
“The placenta is the vital interface between the mother and foetus, serving as the lifeline for foetal growth and development,” write the authors of the study in the Journal of Translational Medicine.
“This transient organ facilitates transport of oxygen and essential nutrients, whilst also protecting the foetus from immune rejection by the mother. Beyond these fundamental roles, the placenta functions as a major endocrine organ, secreting a wide range of hormones crucial for maternal support of pregnancy.”
Pregnant female mice which did not have bacteria in their guts were either administered 3 doses of oral B. breve or remained germ-free. As a result, the researchers found that more than 150 processes in the placenta, involving more than 400 proteins, were different between mice with or without the bacteria in their gut.
“Our results open up an entirely new way to assess the health of a pregnant mother and her developing foetus by looking at the mother’s gut microbiome,” says Dr Jorge Lopez Tello, first author of the report from the UK’s University of Cambridge and Spain’s Autonomous University of Madrid.
“Everybody ignores the placenta – after 9 months of pregnancy it just gets thrown in the bin. But now we understand more about how it works, in the future pregnancy complications like gestational diabetes, preeclampsia, miscarriage and stillbirth might be prevented simply by adjusting the mother’s gut microbes to improve the function of the placenta.”