Complement in breast milk modifies offspring gut microbiota to promote infant health. (https://pubmed.ncbi.nlm.nih.gov/38242132/)

These scientists wanted to understand why breastfeeding is so good for babies. They knew that breast milk has special things called complement components, but they didn't know exactly what these components do. So, they did an experiment using mice to find out.

First, they had some mice moms that didn't have the complement components in their milk, and they had other mice moms that had the complement components in their milk. Then, they gave the baby mice a germ called Citrobacter rodentium (CR) to see what would happen.

The baby mice that drank milk without the complement components got very sick and couldn't fight off the germ. But the baby mice that drank milk with the complement components were able to handle the germ and didn't get sick.

The scientists discovered that the complement components in breast milk can directly kill certain types of bacteria in the baby's gut. This helps to keep the baby healthy and protects them from harmful germs like CR.

So, the scientists found out that breast milk with complement components can shape the baby's gut bacteria to be strong and protect against bad germs. That's why breastfeeding is so important for newborns and infants.

Xu D., Zhou S., Liu Y., Scott AL., Yang J., Wan F. Complement in breast milk modifies offspring gut microbiota to promote infant health. Cell. 2024 Feb 1;187(3):750-763.e20. doi: 10.1016/j.cell.2023.12.019. Epub 2024 Jan 18.