Maternal Fecal Microbiota Transplantation in Infants Born by Cesarean Section Rapidly Restores Normal Gut Microbial Development–A Proof of Concept Study

Infants born by vaginal delivery are colonized with maternal fecal microbes. Cesarean section (CS) birth appears to disrupt the mother-to-neonate transmission and hence has persisting effects on the immune development of the infant. We evaluated whether the normal intestinal microbiota development observed in vaginally born infants could be restored in CS-born infants by immediate postnatal, orally delivered fecal microbiota transplantation (FMT) from their own mothers. After careful screening for health, clinical parameters and presence of pathogens, seven out of seventeen mothers were selected. Their infants received in the first breast milk feeding a single dose of a diluted fecal sample of their own mothers (containing approximately 106-107 cells) that had been taken 3 weeks prior to delivery, analyzed and stored appropriately. All seven infants had an uneventful clinical course during the three-months follow-up, during which fecal samples were collected. Time series of the fecal microbiota composition of the FMT-treated CS-born infants were compared with that of vaginally born and CS-born infants from the same hospital as well as global datasets. Remarkably, the FMT changed the microbiota of CS-born infants that no longer resembled that of untreated CS-born infants but showed significant similarity with that of the vaginally born infants, both in overall composition and development of early-life signature bacteria. While providing direct support for the maternal transfer of fecal microbiota that naturally occurs during birth, this proof-of-principle study demonstrates that the intestinal microbiota and its normal development in early life can be rapidly postnatally restored by maternal FMT. Whereas this simple and affordable procedure should only be applied after careful screening in term infants, it may contribute to mitigating potential adverse health effects that have been associated with CS delivery.