Breast milk-derived extracellular vesicle miRNAs are associated with maternal asthma and atopy.

Maternal asthma is associated with child health outcomes, although the biological mechanisms involved are not fully understood. miRNAs are small molecules involved in regulating gene expression. miRNAs packaged into membrane-bound particles called extracellular vesicles (EVs) are present in human breast milk and may pass from mother to infant to signal which genes to translate into proteins. This study investigated the extent to which maternal asthma and atopy influenced levels of 130 EV miRNAs measured in breast milk. Nine EV miRNAs were associated with maternal asthma during pregnancy, and one EV miRNA was associated with maternal atopy. miRNAs associated with asthma target genes in pathways related to asthma; however, future research is needed to determine whether changes in breast milk-derived EV miRNAs impact child health.