Experiencing stress during pregnancy may affect offspring's development by making changes to a mother's vaginal microbiota composition, according to researchers.
During vaginal birth, microbiota that populate the mother's vagina are passed on to the baby. This microbiota aid normal colonization of the child's gut, helping immune system and metabolism development.
According to the researchers, including study co-author Tracy Bale, PhD, of the University of Pennsylvania, since vaginal microbiota influences offspring's gut colonization during an important stage of brain development, it is believed such microbiota also influences brain development.
For their study, Bale and colleagues set out to assess how stress during pregnancy may affect the population of microbes within a mother's vagina, and how this may influence the gut microbiome and brain development of offspring.
They did so by exposing pregnant mice to stress triggers during early pregnancy, such as new noises, predator odors and restraint.
The researchers collected tissue from the vaginal lavages of the mice 2 days after they gave birth, in order to assess their vaginal microbiome.
The team investigated the gut microbiome of the mouse pups by analyzing their feces, and they also analyzed the transportation of amino acids from the gut of the pups to their brain.
Findings highlight the important role of the vaginal microbiome in offspring development
The researchers found that mice exposed to stress during early pregnancy experienced alterations in their vaginal microbiome, which disrupted the gut microbiota composition of their offspring.
The team found that male offspring was particularly prone to gut microbiome disruption as a result of changes to a mother's vaginal microbiome.
"Mom's stress during pregnancy can impact her offspring's development, including the brain, through changes in the vaginal microbiome that are passed on during vaginal birth," explains Bale.
"As the neonate's gut is initially populated by the maternal vaginal microbiome," she adds, "changes produced by maternal stress can alter this initial microbe population as well as determine many aspects of the host's immune system that are also established during this early period."
The team says their findings emphasize the importance of a mother's vaginal microbiome for populating the gut microbiome of offspring during childbirth, highlighting the negative effects maternal stress may have on this crucial process.
Commenting on the importance of their findings, Bale says:
"These studies have enormous translational potential, as many countries are already administering oral application of vaginal lavages to C-section delivered babies to ensure appropriate microbial exposure occurs.
Knowledge of how maternal experiences such as stress during pregnancy can alter the vaginal microbiome is critical in determination of at-risk populations."
In February, Medical News Today reported on a study published in Nature, in which researchers found that bacterial DNA can be passed from mother to child. What is more, they found the transfer of this bacterial DNA may influence offspring's immunity.