THIS ARTICLE FIRST APPEARED ON NPR.
As a new parent, Jack Gilbert got a lot of different advice on how to properly look after his child: when to give him antibiotics or how often he should sterilize his pacifier, for example.
After the birth of his second child, Gilbert, a scientist who studies microbial ecosystems at the University of Chicago, decided to find out what’s actually known about the risks involved when modern-day children come in contact with germs.
“It turned out that most of the exposures were actually beneficial,” Gilbert says. “So that dirty pacifier that fell on the floor — if you just stick it in your mouth and lick it, and then pop it back in little Tommy’s mouth, it’s actually going to stimulate their immune system. Their immune system’s going to become stronger because of it.”
Gilbert is now the co-author of a new book called Dirt is Good: The Advantage of Germs for Your Child’s Developing Immune System. Presented in a Q&A format, the book seeks to answer many of the questions Gilbert has fielded from parents over the years.
What are some things that parents get wrong?
Some of the main things are over-sterilizing their environment, keeping their children from ever getting dirty. So going out into the backyard and playing in the mud, and then as soon as they’re filthy, bringing them in and sterilizing their hands with antiseptic wipes, and then making sure that none of the dirt gets near their faces. Also, keeping them away from animals. The dogs and cats, sure, but also, other animals. It’s fine to wash their hands if there’s a cold or a flu virus around, but if they’re interacting with a dog, and the dog licks their face, that’s not a bad thing. In fact that could be extremely beneficial for the child’s health.
What about hand sanitizer? Good or bad?
Usually bad. Hot, soapy water is fine. Even mildly warm, soapy water is fine, and it’s probably less damaging to the child’s overall health.
How about the five-second rule? The idea that if something falls on the ground and is there for under five seconds, it’s clean.
The five-second rule doesn’t exist. It takes milliseconds for microbes to attach themselves to a sticky piece of jammy toast, for example. But it makes no difference. Unless you dropped it in an area where you think they could be a high risk of extremely dangerous pathogens, which in every modern American home is virtually impossible, then there’s no risk to your child.
Wash a pacifier or lick it if it falls on the ground?
Lick it. A study of over 300,000 children showed that parents who licked the pacifier and put it back in — their kids developed less allergies, less asthma, less eczema. Overall, their health was stronger and more robust. [Editor’s note: See the correction below. Just 184 children were involved in the study.]