Breast Milk Makes Immune System Strong

Supporting the benefits of breast-feeding and the ability of mother's milk in protecting infants from infections and illnesses, scientists have identified a mechanism that makes breast milk superior to infant formula.

Scientists from Duke University Medical Center have found that breast milk promotes microbiotic flora in a newborn's intestinal tract that helps in the absorption of nutrients and strengthens the immune system.

"This study is the first we know of that examines the effects of infant nutrition on the way that bacteria grow, providing insight to the mechanisms underlying the benefits of breast-feeding over formula feeding for newborns," Dr. William Parker, associate professor of surgery at Duke and senior author of the study, said in a statement. "Only breast milk appears to promote a healthy colonization of beneficial biofilms, and these insights suggest there may be potential approaches for developing substitutes that more closely mimic those benefits in cases where breast milk cannot be provided."

For their study, Parker and team grew bacteria in three different types of milk - infant formula (three brands of popular milk- and soy-based products), cow's milk and mother's milk (processed, fats and proteins separated). 

An antibody called secretory immunoglobulin A (SlgA) that helps in building an infant's immunity was also taken for experiments.  

The antibody, along with the infant formula and milk products, were incubated with two strains of E. coli.

In breast milk, the bacteria grew, building a shield against pathogens and infections. Though the bacteria in the infant formula and cow's milk grew widely, a protective barrier couldn't be built.

"Knowing how breast milk conveys its benefits could help in the development of infant formulas that better mimic nature," Parker said. "This could have a long-lasting effect on the health of infants who, for many reasons, may not get mother's milk."

Breast-feeding benefits both the mother and her infant. Health experts from the World Health Organization and the American Academy of Pediatrics advise new mothers to breast-feed their babies until the sixth month, since formula milk is not as effective as breast milk in preventing a number of illnesses among babies. 

"This study adds even more weight to an already large body of evidence that breast milk is the most nutritious way to feed a baby whenever possible," Gabriela M. Maradiaga Panayotti, co-director of the newborn nursery for Duke Children's and Duke Primary Care said. "We know that babies who receive breast milk have better outcomes in many ways, and mothers who breast-feed also have improved health outcomes, including decreased risks of cancer. Whenever possible, promoting breast-feeding is the absolute best option for mom and baby."

The findings have been published in the August issue of the journal Current Nutrition & Food Science.