Editorial comments on: “Immune‐related microRNAs in breast milk and their relation to regulatory T cells in breastfed children”

Abstract

Editorial comments on: "Immune-related microRNAs in breast milk and their relation to regulatory T cells in breastfed children"Primary prevention is an area of wide interest for the prevention of allergies, with early-life interventions yielding a high potential of intervention. Various strategies have investigated dietary interventions during pregnancy, or earlylife feeding patterns, however, with variable levels of efficiency. 1,2 Among these, lactation with human breast milk finds is widely supported due to its many beneficial aspects; however, controversy still remains about whether breastfeeding can prevent the development of allergic disease. 3 In the quest of deciphering the beneficial mechanisms behind the potential preventive effect of breast milk, various authors have recently evoked the role of metabolites such as caprylate or acetate, 4 or of modulation of IgA levels, 5 but also potentially of micro-RNAs and the gut microbiome. 6,7 We highlight here as editor's choice the recent study by Ahlbers et al. which postulated that the expression of immune-related miRNAs in breast milk is influenced by pre-and postnatal supplementation with Limosilactobacillus reuteri and omega-3 polyunsaturated fatty acids through immunomodulation by infant's regulatory T cells. 8 miRNA are small noncoding RNAs that can modulate gene expression on a posttranscriptional level. In breast milk, they are encapsulated in extracellular vesicles and might be involved in immunomodulatory pathways, for example, in the development and maturation of T cells. Breast milk was collected from mothers with a history of allergic diseases enrolled in a randomized controlled trial to receive Limosilactobacillus reuteri with or without omega-3 polyunsaturated fatty acids. Infant blood was collected at 6, 12, and 24 months and analyzed for regulatory T-cell subpopulations.