Jason Newland, MD, MEd, a Washington University infectious diseases physician at St. Louis Children’s Hospital, explains how.

Q: When can germs be “good”?

We all have a community of bacteria, fungi and viruses that live on our skin, in our intestines and in our mouths. It’s called the “microbiome.” Sometimes, these germs can be helpful. For example, gut bacteria help us digest food. But sometimes, germs can make us sick.

Q: Should parents worry about kids being “too clean”?

Kids should be kids. That means playing in the mud and having a good time. As parents, we should focus on what we know prevents infections. That includes washing hands, covering mouths when we cough and getting all of our immunizations.

Q: How else can parents protect children from bad germs without hurting the good ones?

Families can be a big help to doctors by asking if antibiotics are really needed. Antibiotics are important medicines, but they can change gut bacteria in ways that may not be helpful. Use them as directed and only when needed.

Have questions about germs? Ask your child’s pediatrician. If you need help finding one, call St. Louis Children’s Hospital at 314.454.KIDS (5437) or toll-free at 800.678.KIDS.