We already know the significant differences in key bacterial prevalence in the mouths of breastfed and non-breastfed babies and the existence of interactions between breast milk and the baby's saliva, their synergy being able to reinforce innate immunity by regulating the oral microbiome of the baby. new born. This study from the Queensland University of Technology confirms this key role of breastfeeding in forming a healthy oral microbiome and shows that mixing breast milk and saliva inhibits the growth of bad bacteria, up to 24 hours later.
Results that confirm that breast milk is much more than just a source of nutrition for babies, because it plays this key role in the formation of a healthy oral microbiome, summarizes Dr Emma Sweeney professor at the Institute of Health and Biomedical Innovation from the University of Queensland. His previous research had already revealed that the interaction of neonatal saliva and breast milk releases antibacterial compounds, including hydrogen peroxide.
An enzyme called xanthine oxidase: breast milk is rich in an enzyme called xanthine oxidase which acts on two substrates, present in the saliva of babies. The release of hydrogen peroxide by this interaction also activates the lactoperoxidase system which produces additional compounds with also antibacterial activity: these compounds participate in the regulation of the growth of different microorganisms.
The oral microbiota of the newborn, an important factor for its health and well-being: when researchers expose a variety of microorganisms to mixtures of breast milk and saliva, they find that the growth of certain microorganisms is inhibited, immediately and for a maximum of 24 hours. This is observed for bacteria considered or not as pathogenic, or even commensal. Overall, the team finds that changes in these bacterial communities in newborns have important implications for the risks of infection or disease early in life. " While the oral microbiota in adults is rather stable, the microbiota in the mouth of newborns is much more dynamic and appears to be diet-mediated during the first months of life ”.
Thus, the combination of breast milk and saliva plays an important role in the formation of a healthy oral microbiota during the first months of life, but it also has important consequences for premature babies or tube-fed babies. Because in these cases, breast milk and babies' saliva do not mix and infants therefore do not receive the benefits of the antibacterial compounds released during breastfeeding.
And this beneficial effect does not necessarily stop at the mouth… The researchers believe that this antimicrobial activity observed in the mouth could also continue in the baby's stomach and intestines…