# The biological modifications of milk are linked to mental health of mothers of infants affected by bronchiolitis

## TL;DR

This study shows that maternal mental health affects the levels of cell-derived particles in breast milk, which may influence infant health.

## Contribution

It is the first to link maternal mental health with extracellular vesicle concentrations in breast milk from infants with bronchiolitis.

## Key findings

- Higher maternal resilience is linked to lower neutrophilic and endothelial EVs in breast milk.
- Increased anxiety scores correlate with higher levels of B-lymphocyte and multiple inflammatory cell-derived EVs.
- Stress and anxiety are associated with elevated concentrations of inflammatory EVs in breast milk.

## Abstract

Breast milk is a dynamic type of nourishment that changes based on the needs of the child. An increasing amount of data suggests that mental health may be an important factor in such modulation. In addition, breast milk contains extracellular vesicles (EVs), which are currently considered an important dynamic system of communication between cells, even of different individuals.

Purpose of this article is to investigate whether changes in breast milk in terms of EVs concentrations are related to maternal mental health.

This is a case-control study for which we enrolled mothers of infants with bronchiolitis (N=33) and mothers of healthy infants (N=13). Breast milk samples were taken and EVs concentrations were quantified. Maternal mental health was assessed by administration of five different psychometric scales: Edinburgh Postnatal Depression Scale (EPDS), State Trait Anxiety Inventory (STAI-S, STAI-T), Barkin Index of Maternal Functioning (BIMF), The Connor-Davidson Resilience Scale 10 items (CD-RISC). Subsequently, scale scores were related to evs concentrations by negative binomial regressions adjusted for case-control.

As maternal resilience increases, the EVs of neutrophilic origin (p=0.0447) and those of endothelial origin (p=0.0078) decrease¹. In contrast, an increased EPDS score is associated with higher levels of B-lymphocyte EVs (p=0.0376). Scores on the STAI-S scale impact many more populations of EVs²: we observed an increased Incidence Rate Ratio (IRR) of neutrophil-derived EVs (p<0.0001), T-lymphocyte- derived EVs (p=0.0214), NK-cell-derived EVs (p=0.0202), T-reg CD4+ CD25+ (p=0.0141) and endothelial marked EVs (p=0.0180). An increase in STAI-T scale scores also was associated with a significant increase in CD177+ neutrophil-derived EVs (p=0.0028) and endothelial-derived EVs (p=0.0111)³.

Image:

Image 2:

Image 3:

EVs concentrations in breast milk are associated with maternal mental health. Specifically, stress and related severity of anxiety is able to increase the concentrations of EVs derived from inflammatory cells, which suggests an increase in their number and activity. Further research is needed to confirm these preliminary findings.

None Declared