Differential microRNAs and metabolites in the breast milk of mothers with adverse childhood experiences.

Adverse childhood experiences (ACE) can strongly impact the physical and mental health of individuals. Recent evidence further suggests that children born to mothers with a history of ACE are at an increased risk for behavioral and metabolic perturbations. In this study, we investigated the impact of maternal ACE on small RNAs and fatty acids (FAs) in the breast milk from a cohort of Polish mothers (n = 103) and ascertained their association with early temperament of their children. Small RNA sequencing followed by qPCR assays were performed to compare small RNAs in the milk from lactating mothers with high vs. low ACE. Additionally, milk from mothers with high vs. low ACE were compared on the short-, middle-, and long-chain FAs content. Our study revealed distinct microRNA and FA signatures of ACE in human breast milk; with increased expression of miR-142-3p, miR-142-5p, and miR-223-3p and reduced levels of middle chain FAs (MCFAs) in the breast milk of mothers with high ACE. Furthermore, a positive correlation was observed between the milk expression of miR-142-3p, miR-142-5p, and miR-223-3p and the ACE score in the mothers. Finally, milk expression of miR-142-5p and MCFAs correlated with infant temperament at the age of 5 and 12 months. The observed associations were not confounded by symptoms indicative of postpartum depression in the mothers. In conclusion, this study newly reveals changes in milk miRNAs and FAs as signatures of ACE in humans and highlights their potential as predictors of intergenerational transmission of the effects of ACE.