So there you are, hanging out with your baby and oh, whoops — his or her pacifier hits the ground. Most parents would take it to the sink, run it under some water or perhaps sterilize it in boiling water to prevent their baby from sucking on germs. But a new study says if you want to help your baby, you should really just suck on that pacifier to clean it off. Say whatnow?

Sure, it sounds gross, and of course if a pacifier lands on the street in a puddle of who knows what, no parent is going to pop that in their mouth. But according to a study in this week’s issue of Pediatrics (via NPR), babies might be less likely to develop allergic reactions as their parents saliva can actually change the makeup of the bacteria that live in and on our bodies.

Those microbiomes could help babies from developing things like asthma and eczema, researcher say. The 65 babies whose mother or father sucked on their pacifiers to clean them off were significantly less likely to develop those conditions, compared to the babies whose parents cleaned the pacifiers with water.

The researchers looked at the data they had on a bigger study about babies’ allergies, and found that some parents answered that they cleaned the pacifier when it fell out of their child’s mouth.

“We asked them how they cleaned the pacifier — if they rinsed them in water — and of course most of them did,” said the study’s author. Sure, some used water, but others?

“They put it in their mouth, sucked on it and then gave it back to the children,” he says. “It’s a quite common way to clean pacifier.”

Researchers think that when a parent does this, it transfers some of their harmless bacteria to their kids, a theory supported by analyzing the babies’ saliva in the study.

“We think that these bacteria … stimulate the immune system,” said the researcher, which sort of teaches the children’s bodies to do its job and fight the urge to develop an allergy.

This is along the lines of the “let kids play in the mud and get dirty” way of viewing child rearing, as opposed to trying to shield children from every little yucky thing out there. Early exposure to these microbiomes could be a good thing, after all. But again, if that pacifier falls in a pile of garbage, go ahead and use regular water. No one will fault you for that.

Parents’ Saliva On Pacifiers Could Ward Off Baby’s Allergies [NPR]

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.