RESUMEN
Infants born by vaginal delivery are colonized with maternal fecal microbes. Cesarean section (CS) birth disturbs mother-to-neonate transmission. In this study (NCT03568734), we evaluated whether disturbed intestinal microbiota development could be restored in term CS-born infants by postnatal, orally delivered fecal microbiota transplantation (FMT). We recruited 17 mothers, of whom seven were selected after careful screening. Their infants received a diluted fecal sample from their own mothers, taken 3 weeks prior to delivery. All seven infants had an uneventful clinical course during the 3-month follow-up and showed no adverse effects. The temporal development of the fecal microbiota composition of FMT-treated CS-born infants no longer resembled that of untreated CS-born infants but showed significant similarity to that of vaginally born infants. This proof-of-concept study demonstrates that the intestinal microbiota of CS-born infants can be restored postnatally by maternal FMT. However, this should only be done after careful clinical and microbiological screening.