The development of a healthy immune system depends in part on being exposed to bacteria, so that the body’s own defences can spring into action.

However, relatively little research has been done into how diet, microbial content in the gut, and overall immune health are linked – particularly in babies.

A team led by Texas A&M University have now studied differences between three-month-old babies who were breastfed and those raised only on infant formula.

Published in the journal Genome Biology, the article notes that breastfed babies have a wider variety of microbes in their intestines – however, they also have a stronger immune system in order to cope.

“Our findings suggest that human milk promotes the beneficial crosstalk between the immune system and microbe population in the gut, and maintains intestinal stability,” says the university’s Robert Chapkin.

The study did not require any invasive procedures to be performed on the infants, as intestinal cells are excreted naturally, allowing them to be studied easily outside of the body.

However you choose to feed your baby, there are some bacteria that will always pose a threat to your infant’s health, so it’s important to cleanse and sterilise feeding equipment and bottles before each use.