Mothers who breastfeed babies in the first month are helping influence the nature of bacteria in the infant's digestive system, which in turn boosts the immune system to provide protection against conditions like allergies or asthma, researchers say.
Scientists at Henry Ford Hospital in Detroit found breastfeeding exposes a baby to the mother's personal assortment of microorganisms in the gastrointestinal tract, which in turn influences how the baby develops T-cells, white blood cells essential for immune system development.
"Our studies are showing that the microbiome that is within a baby's gastrointestinal tract is very important in disease [immunity] development," says researcher Christine Cole Johnson.
The new studies confirm what many experts have long believed, that a completely sterile environment is not what is best for babies, says Johnson, head of the public health sciences department at Henry Ford.
Bacteria introduced into the baby's gut through breastfeeding is important, she says.
"Exposure to these microorganisms, or bacteria, in the first few months after birth actually help stimulate the immune system," Johnson explains.
Our immune systems are designed to experience exposure to a large variety of bacteria, she notes, and "if you minimize those exposures, the immune system won't develop optimally."
In the study, breastfed babies examined at the age of one month and again at six months of age had distinct gut microbiome compositions as compared with nonbreastfed babies, compositions that could have an effect on immune system development, the researchers say.
The bacterial ecosystem found in gastrointestinal tracts is thought to be involved in a number of diseases like obesity, autoimmune diseases, circulatory disorders and pediatric allergies and infection, researchers say.
The study results were presented in Houston at the annual meeting of the American Academy of Allergy, Asthma & Immunology.
The combination of hormones, cells and antibodies fed to a baby through the mother's breast milk provides a number of protections for the baby, reports the Office on Women's Health, a division of the U.S. Department of Health and Human Services.
The new findings support that, Johnson says.
"For years now, we've always thought that a sterile environment was not good for babies. Our research shows why," she says.
"The research is telling us that exposure to a higher and more diverse burden of environmental bacteria and specific patterns of gut bacteria appear to boost the immune system's protection against allergies and asthma."
