“Is it okay for my kid to eat dirt?”

That’s just one of the many questions we’re bombarded with every day from parents all over the world who are worried about their children’s health and confused about what they’re reading on the Internet.

Why are they asking us?

Because we’re two of the scientists leading the investigation of the human microbiome. That’s often misunderstood as meaning “germs,” but it’s really the community of friendly microbes that populate the human body, as well as a few that, in the wrong context, aren’t so good. This diverse multitude of tiny, invisible creatures helps us out in all kinds of ways, such as digesting food, making vitamins, protecting us from diseases, sculpting our organs, tuning our immune systems, and even shaping our behavior.