Restoring maternal microbes immediately after birth, in a practice dubbed ‘vaginal seeding’, has been suggested as a means of improving microbiome development in cesarean-born neonates. Two new studies come to contradictory findings, however, highlighting the need for more clinical trials before the practice is generalized.

The microbiota of infants born by caesarean section resembles that of maternal oral cavity and skin, whereas that of vaginally born infants resembles that of the maternal gut microbiome. A new proof-of-concept study shows that the gut microbiota of C-section-born infants can be restored after delivery via orally administered maternal fecal microbiota transplantation.