Protein in Breast Milk an Immune Booster 

A protein found in breast milk may keep babies healthier by giving the immune system a welcome boost.

Researchers say the immune system is fragile in early life, which makes babies more vulnerable to infection. Michael Julius, M.D., from the Toronto General Research Institute in Canada, says, "It takes up to a year for an infant's immune system to start to fully function near adult efficiency." Dr. Julius and his colleagues now believe the protein, sCD14, may promote early development of babies' immune systems, helping them fight off infections more effectively.

Researchers studied sCD14 in the laboratory and found it can stimulate B cells. Dr. Julius says, "The body's B cells are involved in the production of infection-fighting antibodies. When we provided baby mice with sCD14, it made their B cells grow and become antibody-secreting cells." Researchers also found there are very high levels of the protein in a woman's breast milk for up to 400 days after giving birth. Dr. Julius cautions they do not know if the protein would work the same way in humans but says the evidence suggests it would.

Dr. Julius says if their finding proves to hold true for humans, it could lead to better baby formulas and ultimately, healthier babies. He adds, "Before anything is added to baby formula it must be absolutely certain that the substance will cause no harm." Results of the study are presented in the January 16th issue of the Proceedings of the National Academy of Sciences.