Breast milk contains more than 700 types of bacteria, found a new study, which also revealed that the bacterial composition of a mother's milk changes as her baby grows and that a woman's body size and the kind of birth she has affect the bacteria that appear in her milk.
The study offers insights into the health benefits of breast milk and hints at how companies might eventually make more nutritious infant formulas.
"If the bacterial composition of human breast milk has co-evolved to maximize the infant's metabolic efficiency and to optimally stimulate the immune system, a skewed microbial milk composition might have important consequences for the infant's health," the researchers wrote in the American Journal of Clinical Nutrition. "Those potential consequences would need to be evaluated for future recommendations in child nutrition."
Breast milk is full of nutrients that protect babies from infections and help their guts cultivate populations of beneficial bacteria. To better understand the breast-milk microbiome, Spanish researchers collected milk from 18 women at three times: within two days of giving birth (when they were producing just colostrum), one month later and six months after delivery.