Apart from being a source of nutrition, breast milk also plays an important role in shaping healthy oral microbiomas in babies, the study suggests.
The study, conducted by the Queensland University of Technology (QUT), showed that growth of some microbes was inhibited up to 24 hours after breast milk and mixing saliva.
This slowdown was whether the microorganism considered "pathogenic" (harmful) or "comentric" (commonly found) in a child's mouth.
This may be because the interaction of neonatal saliva and breast milk releases antibacterial compounds, including hydrogen peroxide, say researchers.
"Mother's milk is high in an enzyme called xanthine oxidase, which acts on two substrates, found in baby saliva," said Emma Sweeney of the Institute of Health and Biomedical Innovation at QUT.
"The release of hydrogen peroxide from this interaction also activates & quot; a system of lactoperoxidase that produces additional compounds that also have antibacterial activity, and these compounds can regulate growth of microorganisms," she added in a paper published in the Scientific Reports.
Sweeney noted that the composition of newborn louse microbes is an important factor in health and well-being.
"Changes in these bacterial communities in newborns have important consequences on early life-related infections or illnesses," she said.
"While oral microbiotics for adults are stable, our studies have shown that microbial in the mouth of newborns is much more dynamic and seems to have been altered by the way of feeding in the first few months of life."
However, this also has significant implications for premature or sick babies that feed on the tube.
"In these cases there is no mixing of the mother's milk and the baby's saliva, so they do not get the benefits of antibacterial compounds released during breastfeeding.
"Other researchers have shown that hydrogen peroxide can remain active at pH values similar to that of a child's stomach, so we think that this antimicrobial activity that can be seen in the mouth can also continue in the stomach and intestines," Sweeney said.