Credit: CC0 Public Domain

Infants delivered by cesarean section have an increased risk of developing asthma and allergies as babies and toddlers, probably because they don’t get exposed to the microbiota in the mother’s vagina and perineum during birth, negatively impacting how their immune systems develop. While a few studies have looked at whether swabbing a newborn’s skin with vaginal fluid immediately after birth reduces this risk, a paper published October 1 in the journal Cell offers a more drastic way to expose newborns to their mother’s microbiota: by diluting a small amount of their mother’s feces in breast milk