These bacteria, called Group B streptococcus, are a common cause of meningitis in newborns and the leading cause of infection in the first three months of life globally.
The bug is carried naturally in the vagina and bowels by up to one in three women and can be transferred to the baby during childbirth or in breast milk.
The new research at Imperial College London on 183 women in The Gambia found that naturally-occurring sugars in a woman's breast milk may have protective effects against Group B streptococcus.
These are not digested in the baby's tummy and act as food for the 'friendly bacteria' in a baby's intestine.
Also Read
The type of sugars a woman produces in her breast milk are partly dictated by her genetic make-up.
A type of genetic system in particular, called the Lewis antigen system, plays an important role in determining breast milk sugars.
The team tested all the mothers' breast milk for the sugars that are known to be controlled by these Lewis genes.
They also tested women and their babies for Group B streptococcus at birth, six days later, and then between 60 and 89 days after birth.
In addition, among the babies who had the bacteria in their guts at birth, the infants whose mothers produced a specific sugar in their breast milk, called lacto-n-difucohexaose I, were more likely to have cleared the bacteria from their body by 60-89 days after birth.
This suggests this breast milk sugar, which is linked to the Lewis gene, may have a protective effect.
The research was published in the journal Clinical and Translational Immunology.
Disclaimer: No Business Standard Journalist was involved in creation of this content