The microbiome refers to the thousands of microorganisms including bacteria that live in and on our bodies. The microbiome plays an important role in our health, and differences in the microbiome can affect our immune system in ways that might make some people more likely to get allergies and asthma.

Early life exposures are very important for establishing the human microbiome. There is information that suggests C-section birth is associated with higher risk of certain diseases including allergies and asthma. Some researchers think one reason for this is that passing through the mother’s vaginal canal during birth exposes the baby to bacteria that promote healthy immune system development, something that C-section babies don’t get. Transferring these potentially beneficial vaginal bacteria to C-section babies may help prevent some diseases later.

The goal of the ACTIVATE study is to look at how differences in the microbiome of a baby may protect, or put a baby at risk, for allergic problems.