Summary: Newborn microbiome differs by mode of delivery and feeding. Newborn C-section microbiome: Swabbing C-section babies partially restores the newborn microbiome.
First, a quick refresher of “How we acquire our gut microbiome.“
Our gut microbiome is acquired at birth, though this is by no means a simple answer. The post “Newborn Gut Microbiome Begins at Birth” details many differences between the newborn gut microbiome due to mode of delivery (vaginal versus C-Section) as well as feeding (breast-fed versus formula-fed). The figure below extends this and shows the recent findings that the developing microbiome is shaped not only by delivery and feeding mode, but that antibiotics, probiotics, and environmental exposures also interact and develops the newborn’s microbiome and resultant immune system.