Impact of vaginal seeding on the gut microbiome of infants born via cesarean section: A systematic review.

OBJECTIVE

This systematic review summarizes eight studies involving 558 cesarean section (CS)-born infants (274 exposed to vaginal seeding (VS), 284 not exposed) and 261 infants born vaginally to investigate the effect of VS on gut microbiome colonization and development in CS-born infants.

METHODS

This study adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant articles published before March 6, 2024, were identified through systematic searches of PubMed, Scopus, and Web of Science. We included experimental studies that investigated changes in the gut microbiota of CS-born infants following VS and reported changes in the gut microbiota. The relationship between VS and the gut microbiota composition of CS-born infants was assessed.

RESULTS

VS may selectively influence the abundance of bacterial genera from various phyla, such as an increased relative abundance of Bacteroides and Lactobacillus, in the gut microbiome of CS-seeded infants compared to CS-non-seeded infants. Conflicting results mainly concern microbial diversity.

CONCLUSIONS

Current evidence indicates modest changes in the gut microbiome of CS-born infants following VS. However, further clinical studies are necessary to fully understand its impact on early-life health outcomes, particularly regarding potential microbiome alterations and associated health risks.