A study published in Metabolites is the first to characterize gut microbe-metabolite mediated pathways for early-life SIgA maturation. The study involving 1017 CHILD Study infants sought to determined the impact of birth mode and breastfeeding status on fecal SIgA levels of infants at 3 and 12 months and identify potential mediating pathways involving infant gut microbiota and metabolites.
Using statistical mediation methods the study identified candidate metabolic pathways involving galactose, fucose, GABA, choline, lactate, pyruvate and 1,2-propanediol to altered gut immunity in young infants following cesarean section delivery. When breastfeeding is lower following cesarean, the reduced availability of these milk and microbiota metabolites leads to lowered SIgA levels in the infant gut. Hence, the benefit of breastfeeding on gut immunity following cesarean delivery is not only direct provision of SIgA to the nursing infant but also promotion of an infant’s own gut SIgA production through milk-related metabolites.