Breastmilk protein osteopontin shown to boost infant immunity against lung infections

A five-year study from QIMR Berghofer Medical Research Institute revealed that the breastmilk protein osteopontin activates biological pathways that jump-start immune system maturation in early life. In experiments, mouse pups receiving osteopontin-rich milk displayed richer gut microbiomes and higher levels of lung-protective immune cells, while those without the protein were more vulnerable to infection. Researchers also showed that a drug used for type-2 diabetes can replicate osteopontin’s immune-boosting actions.

The work, appearing in Cell and funded partly by Nestle and the Australian NHMRC, is now being discussed with formula manufacturers to improve product immunity. Experts praised the discovery but noted that human trials are needed, and they emphasized that expanding breastfeeding support remains the most immediate way to protect infants. The study adds to growing evidence linking early nutrition, microbiome composition, and long-term respiratory health.