Frequent breastfeeding also helps prevent engorgement. Your colostrum provides not only perfect nutrition tailored to the needs of your newborn, but also large amounts of living cells which will defend your baby against many harmful agents. The concentration of immune factors is much higher in colostrum than in mature milk. Before your baby was born, he received the benefit of another antibody, called IgG, through your placenta. IgG worked through the baby's circulatory system, but IgA protects the baby in the places most likely to come under attack from germs, namely the mucous membranes in the throat, lungs, and intestines.
Colostrum has an especially important role to play in the baby's gastrointestinal tract.
A newborn's intestines are very permeable. Colostrum also contains high concentrations of leukocytes, protective white cells which can destroy disease-causing bacteria and viruses. Later, when you are producing mature milk for your baby, the concentrations of the antibodies in the milk will be lower, but your baby will be taking in much higher volumes of milk. The disease-fighting properties of human milk do not disappear with the colostrum. In fact, as long as your baby receives your milk, he will receive immunological protection against many different viruses and bacteria.