Mehmet Oz, M.D., is host of “The Dr. Oz Show,” and Mike Roizen, M.D., is Chief Wellness Officer and Chair of Wellness Institute at Cleveland Clinic. Email questions to youdocsdaily@sharecare.com.

QUESTION: My 1-year-old daughter occasionally drops her pacifier on the ground. I just clean it off in my mouth and hand it back to her.

My mom says that’s awful, but there’s nothing wrong with that, is there? — Annabel T., Abilene, Texas

ANSWER: Generally speaking, there’s nothing wrong with a little “mom juice” to clean off a pacifier. What you’re doing is sharing part of your disease-fighting oral biome with your daughter, and that’s a really good thing. You’re helping boost her immune system (and maybe yours) by introducing a few immune-system-engaging microbes, which helps her fight off chronic problems such as allergies.

(We assume your lawn doesn’t have pesticide on it and that the sidewalk isn’t some urban hot spot — you can gauge those riskier environments, we hope.)

Recently, researchers in Detroit found that moms who cleaned their children’s pacifier by sucking on it have kids who develop fewer allergies. And there’ve been several studies showing that kids who grow up on farms with (naturally germy) animals or with pets in more urban settings are exposed to lots of microbes and have greatly reduced rates of asthma.

These findings lend support to the hygiene hypothesis: a widely held theory that overly cleaned Western environments reduce our exposure to infectious agents and other microbes, and that leaves our powerful immune systems with not much to work on but us! Hence, the big increase in autoimmune disease and allergies in developed countries, while there’s a relative lack of them in the environments of developing countries.

So stick with your pacifier cleaning routine (please use a pacifier with no BPA or BPS in the plastic), but if she drops it somewhere that looks a bit suspicious, don’t make yourself or your daughter sick. Strong immune systems are great, but don’t pay too high a price.