Breast milk is considered nature’s perfect food. Breast milk contains everything an infant needs to grow and develop, including nutrients, immune factors, and prebiotic fibers known as oligosaccharides. It was once thought that the prebiotics found in breast milk were responsible for helping to establish beneficial bacteria in the digestive tracts of growing infants, but a new study is adding to our knowledge of how babies’ digestive tracts are colonized by beneficial bacteria.

The study, published in the journal Environmental Microbiology, found that breast milk actually contains beneficial bacteria that come from the digestive tracts of the mother. They found the same strains of a particular probiotic bacterium, Bifidobacterium breve, in addition to other beneficial Clostridium strains in both the digestive tracts and breast milk of mothers. This is a new discovery. “We are excited to find out that bacteria can actually travel from the mother’s gut to her breast milk,” stated Christophe Lacroix, PhD, lead researcher. The researchers are not sure of the route taken by bacteria into the breast milk, but future studies will investigate this topic further.

What this tells us is that not only is mother’s digestive balance important for baby during pregnancy and birth, but it is also very important during breastfeeding. An infant’s gut bacteria are derived from the mother especially when delivered via the birth canal, and also through breastfeeding. When mother has a healthy balance of gut bacteria, baby is more likely to inherit that balance.