Summary: How Breast Milk Protects Newborns

Doctors have long recognized that breastfed infants contracted far fewer infections than infants who were given formula. The reason is that mother s milk helps infants to fight against foreign organisms during the first few months of life when an infant doesn t have an effective immune system. Not only do breastfed infants have antibodies passed to them during pregnancy to help breakdown bacteria, and viruses, they also gain extra protection from antibodies, other proteins and immune cells passed through the human milk. There are five basic forms of antibodies, denoted as IgG, IgA, IgM, IgD, and IgE. These five have all been found in the human milk. These antibodies seem to shield the antibody molecules from being degraded by the gastric acid and digestive enzymes in the stomach and intestines. Infants who are bottle-fed have few means for battling ingested pathogens until they begin making their own IgA. Also the antibodies delivered to the infant useful bacteria normally found in the gut. This flora serves to crowd out the growth of harmful organisms, resulting in another measure of resistance. Even until know, researchers are dumbfounded on how the mother s immune system knows to make antibodies against only pathogenic and not normal bacteria. This favors the establishment of good bacteria in the baby s gut. Several molecules in human milk prevent microbes from attaching to mucosal surfaces. Human milk contains large molecules called mucins that include a great deal of protein and carbohydrate. One of the oldest known disease-resistance factors in human milk, Bifidus factor, helps promotes growth of beneficial organism named Lactobacillus bifidus. Immune cells are also abundant in human milk. They consist of white blood cells that fight infection themselves and activate other defense mechanisms. The second most common milk leukocyte is the macrophage. The macrophages in breast milk manufacture lysozyme. Lysozyme is an enzyme that destroys bacteria by disrupting their cell walls. Breast milk is truly a fascinating fluid that supplies infants with far more than nutrition.