Mother’s milk has special substances called enzymes, which help the baby’s immature stomach and intestines develop. These enzymes also break down the nutritional parts of the milk and reduce the chance that the baby will develop feeding intolerance, during which feedings must be stopped temporarily.

Another major benefit of mother’s milk is that it provides protection from infection. This is important because premature babies have limited ability to fight bacteria and viruses on their own, and because they are exposed to many germs in the neonatal intensive care unit (NICU).

Mother’s milk has many special defensive agents, including antibodies, that work to protect premature babies from infection. Mothers of premature babies have higher amounts of thesein their milk, especially during the early days of milk production. Some substances “paint” the inside of the baby’s intestines and prevent bacteria and viruses from being absorbed into the bloodstream. Others work directly to kill germs or stop them from growing. Some of the nutrients in the milk serve two purposes. They make it difficult for germs to live and grow in the baby’s intestines, and your baby uses them as “fuel” for growth.

Some of these agents are absorbed into the baby’s bloodstream and may continue to protect against infection even after the baby no longer receives mother’s milk. Mother’s milk also contains antiinflammatory agents, which help protect the premature baby’s fragile bowel tissues from swelling and soreness. This reduces the chance that harmful bacteria can grow. These agents are thought to help defend the baby againstnecrotizing enterocolitis (NEC), a serious bowel condition.