Breastmilk and Immune Function

Breastmilk strengthens host defence mechanisms through innate and adaptive immune development and enhances the immature immunologic system of the neonate during a delicate and crucial period. As well as mammalian evolution, some of the mechanisms that explain active stimulation of the infant's immune system include three major phenomena: (1) human milk accelerates the maturation of gut barrier function in the otherwise immature neonatal mucosa; (2) a range of innate and adaptive immune factors in human milk protect the neonate and young infant from pathogenic damage; and (3) components in human milk actively modulate inflammatory reactions. Breastmilk feeding of newborns has been associated with reduced disease in early infancy and later life that may be attributed to many of the bioactive factors identified in milk such as extracellular vesicles, exosomes, microRNA, stem cells, cytokines, hormones, growth factors, colony-stimulating factors, and the nutrients, oligosaccharides, lipids, and proteins that promote optimum development and protect against disease.

Our current knowledge of the mechanisms whereby human milk impacts on infant immunological development provides evidence that breastfeeding should be promoted.

All mothers should be encouraged and supported to exclusively breastfeed for at least the first 6 months of life. Breastfeeding and complementary foods beyond 6 months is recommended up to 2 years, to promote optimum health of the child.