Contrary to popular belief, an infant's gut microbiome is not primarily shaped by the mother's vaginal microbiome, a new study indicates. The findings suggest that practices such as vaginal seeding are ineffective.
A longitudinal, prospective cohort study of more than 600 pregnant Canadian women and their newborns showed significant differences in an infant's stool composition by delivery mode at 10 days post partum, but the differences could not be explained by the mother's vaginal microbiome, and they effectively disappeared by 3 months.
Scott Dos Santos
The findings were surprising, Scott Dos Santos, a PhD candidate at the University of Saskatchewan in Saskatoon, Canada, told Medscape Medical News. "The bacteria living in the maternal vagina are the first microbes that vaginally delivered infants are exposed to...so it sounds intuitive that different kinds of vaginal microbiomes could end up influencing the development of a baby's gut microbiome in different ways. But the maternal vaginal microbiome didn't seem to have any role in predicting what the infant stool microbiome looked like."
Therefore, women should not be concerned about cesarean delivery having an adverse effect on their baby's gut microbiome, said Dos Santos. Moreover, "vaginal seeding is not safe or advised. Professional bodies, including the Society of Obstetricians and Gynecologists of Canada and the American College of Obstetricians and Gynecologists, strongly advise against this practice."
