Cesarean delivery and the neonatal microbiome
Research has shown that route of delivery has an effect on the microbiome of newborns. A new study conducted in Europe shows that cesarean delivery may prevent mother-to-child transmission of some microbial strains during a key point in immune system development.
The findings, published in Nature Communications, are from an analysis of the earliest gut microbial community structures and functions in 33 neonates, half of whom were born via cesarean delivery and half vaginally. The authors used 16S rRNA gene amplicon sequencing and high-resolution metagenomics for the research.
Stool samples were collected from the infants at ≤ 24 hours, 3 days, and 5 days postpartum. The microbiome in them was compared with those in samples from stool and vaginal swabs taken from their mothers less than 2 hours before delivery.
The authors said they found that cesarean delivery prevents certain bacteria that ordinarily interact with an infant’s immune system from being passed from mother to child. Levels of TNF-αand IL-18 were higher in the feces from the vaginally delivered neonates than in those born via cesarean, as were levels in neonatal blood plasma.
The microbial composition between the two groups of infants differed most strongly on Day 3 postpartum. The earliest gut microbiome in the infants born via vaginal delivery also had higher immunostimulatory potential than the microbiome in the infants born via cesarean.
Their results, the researchers said, “support that cesarean delivery disrupts mother-to-neonate transmission of specific microbial strains, linked functional repertoires and immune-stimulatory potential during a critical window for neonatal immune system priming.” They believe the bacterial colonizer-immune system link, with other factors, may explain why infants born via cesarean are statistically more prone to develop allergies, chronic inflammatory diseases and metabolic diseases. Further investigation is warranted, said the authors, of ways to replace the maternal bacterial strains that are lacking in babies born via cesarean.