Colonization of the gut begins in early life and is highly influenced by method of birth (vaginal versus Caesarean), method of feeding (formula feeding versus breastfeeding), and exposure to antibiotics1. It is known that babies pick up microbes from their environment and their mother’s microbiomes, such as the mouth, skin, vagina, gastrointestinal tract, and breasts.
Research has shown that babies born vaginally have different gut bacteria than those delivered by Caesarean. Published in Nature this year, the largest study ever on neonatal microbes discovered that whereas vaginally born babies got most of their gut bacteria from their mother, babies born via caesarian acquire more bacteria associated with hospital environments in their guts 2. Researchers also discovered that most of the microbiome of vaginally delivered newborns did not come from the mother’s vaginal bacteria, but from the mother’s gut.
This is new information since previous studies suggested that vaginal bacteria were swallowed by the baby on its way down the birth canal. However, this large-scale study found babies had very few of their mother’s vaginal bacteria in their guts, with no difference between babies born vaginally or by cesarean.
Babies pick up microbes from their enivronment and their mother. Image credit Danger Insitute, Genome Research.