Paper
Friday, July 13, 2007
Biobehavioral Evidence that Human Milk is the Product of Unique Maternal Infant Dyad Interactions: Implications for Nursing Practice
Maureen Wimberly Groer, RN, PhD, FAAN, College of Nursing, University of South Florida, Tampa, FL, USA
| Learning Objective #1: describe the immunology of human milk and the factors known to alter milk's composition |
| Learning Objective #2: discuss the implications of the research findings with regard to facilitation of the health of the maternal-infant dyad |
Breastfeeding mothers produce milk which meets unique immunological needs of nursing infants. When exposed to infectious agents, mothers produce milk that contains specific antibodies to these microbes to protect the infant. Many factors potentially could interfere with immunological competence of milk. Fatigue, depression and stress in nursing mothers have the potential to alter maternal neuroendocrinology and immunology but effects on human milk have not been studied extensively. We explored relationships between unique aspects of maternal physiology and maternal and infant health in breastfeeding mothers. Twenty nine cytokines were measured in a multiplex assay of 32 samples of human hindmilk whey, collected at the first morning feed in exclusively breastfeeding mothers at 4-6 weeks postpartum. Secretory IgA (sIgA) in milk was measured by ELISA. Serum values of cytokines and hormones were determined from blood collected at the same time. Mothers were healthy and had normal deliveries and healthy infants. Proinflammatory cytokines and chemokines were low while proimmune and growth promoting cytokines were high (nanogram range). Some chemokines were also high. Demographic factors were not related to cytokines, nor were there relationships between dysphoric moods, stress scores and cytokines. However womens’ reports of symptoms of infection, were highly correlated with milk IgA, proinflammatory cytokines and chemokines. Serum levels of cortisol, Interferon-gamma and IL-2 were also significantly correlated with many milk proinflammatory cytokines and chemokines. These data suggest that breastfeeding mothers are stress-resistant in terms of milk immunology, and are able to produce milk that is higher in proinflammatory cytokines , chemokines and secretory Immunoglobulin A when they have infections which could potentially threaten the infant. These data provide further evidence of benefits of human milk, and suggest that lactating mothers are stress resistant in terms of milk immunology, but most responsive to environmental threats such as infectious illness.