Mother-to-Infant Microbial Transmission from Different Body Sites Shapes the Developing Infant Gut Microbiome
The acquisition and development of the infant microbiome are key to establishing a healthy host-microbiome symbiosis. The maternal microbial reservoir is thought to play a crucial role in this process. However, the source and transmission routes of the infant pioneering microbes are poorly understood. To address this, we longitudinally sampled the microbiome of 25 mother-infant pairs across multiple body sites from birth up to 4 months postpartum. Strain-level metagenomic profiling showed a rapid influx of microbes at birth followed by strong selection during the first few days of life. Maternal skin and vaginal strains colonize only transiently, and the infant continues to acquire microbes from distinct maternal sources after birth. Maternal gut strains proved more persistent in the infant gut and ecologically better adapted than those acquired from other sources. Together, these data describe the mother-to-infant microbiome transmission routes that are integral in the development of the infant microbiome. ; his study was supported by Fondazione CARITRO fellowship Rif. Int. 2013.0239 to N.S. The work was also partially supported by the European Research Council (ERC-STG project MetaPG-716575), MIUR "Futuro in Ricerca" RBFR13EWWI_001, the People Program (Marie Curie Actions) of the European Union Seventh Framework Program (FP7/2007–2013) under REA grant agreement no. PCIG13-GA-2013-618833, the LEO Pharma Foundation to N.S., and a European Union H2020 Marie-Curie grant (707345) to E.P. ; Peer reviewed