Human milk cortisol and immune factors over the first three postnatal months: Relations to maternal psychosocial distress

Abstract

Background Many biologically active factors are present in human milk including proteins, lipids, immune factors, and hormones. The milk composition varies over time and shows large inter-individual variability. This study examined variations of human milk immune factors and cortisol concentrations in the first three months post-partum, and their potential associations with maternal psychosocial distress. Methods Seventy-seven healthy mothers with full term pregnancies were enrolled, of which 51 mothers collected morning milk samples at 2, 6 and 12 weeks post-delivery. Maternal psychosocial distress was assessed at 6 weeks post-delivery using questionnaires for stress, anxiety, and depressive symptoms. Immune factors were determined using multiplex immunoassays and included innate immunity factors (IL1β, IL6, IL12, IFNγ, TNFα), acquired immunity factors (IL2, IL4, IL10, IL13, IL17), chemokines (IL8, Groα, MCP1, MIP1β), growth factors (IL5, IL7, GCSF, GMCSF, TGFβ2) and immunoglobulins (IgA, total IgG, IgM). Cortisol was quantified using liquid chromatography-tandem mass spectrometry. A linear mixed effects model was fit to test whether stress, anxiety, and depressive symptoms individually predicted human milk cortisol concentrations after accounting for covariates. Repeated measurement analyses were used to compare women with high (n = 13) versus low psychosocial distress (n = 13) for immune factors and cortisol concentrations. Results Virtually all immune factors and cortisol, with the exception of the granulocyte-macrophage colony-stimulating factor (GMCSF), were detected in the human milk samples. The

The Association between Maternal Stress and Glucocorticoid Rhythmicity in Human Milk

“…Findings from previous studies investigating associations between experienced stress and GC level or rhythmicity in various samples [ 22 ], including serum [ 14 , 23 ], saliva [ 13 , 16 , 24 ], (early morning, spot or 24 h) urine [ 15 ], hair [ 25 ] and milk [ 12 , 26 , 27 ], were contradictory. There are several explanations for these different findings.…”

“…In addition, not only the number of samples is important, but also the timing of sampling. One study suggested that women with increased psychological stress collected their morning samples approximately three hours after awakening versus half an hour post-awakening in women with low stress experience [ 12 ]. Since GCs reach their highest value approximately 30–45 min after awakening, it might be possible that the lack of association could be attributed to between-group differences in sampling times [ 28 ].…”

“…The GC composition in human milk may be influenced by various factors, including maternal stress, weight, educational status and parity [ 9 , 11 , 12 ]. Studies addressing the relation between maternal stress and GC levels in human milk are scarce [ 9 ].…”

Milk and Dairy Products: Good or Bad for Human Bone? Practical Dietary Recommendations for the Prevention and Management of Osteoporosis

“…However, two weeks after the stressful situation, the level of cortisol in milk was significantly higher. Moreover, breast milk also contains growth hormones [ 19 , 29 ].…”

Obesogenic Programming Effects during Lactation: A Narrative Review and Conceptual Model Focusing on Underlying Mechanisms and Promising Future Research Avenues

“…Maternal stress may also be linked to child obesity [ 37 , 38 , 39 ], but the mechanisms explaining this link are largely unknown. We propose two main pathways that may explain this link during lactation (see Figure 1 ), that is, one physiological pathway (i.e., through human milk composition) [ 40 , 41 ] and one behavioral one (i.e., through maternal lifestyle and weight-related parenting) [ 42 , 43 ] affecting child weight-related behaviors [ 44 ]. Future research may examine whether and how intervention on maternal stress may impact human milk components and child weight outcomes through lactation-specific pathways (i.e., child satiety and eating characteristics, child gut microbiota, and flavor exposure).…”