It’s a scene all-too-familiar to parents of toddlers. The tiny human’s pacifier hits the floor, you swoop in to pick it up before the screaming begins — then what? Do you stick it right back into your child’s wailing mouth or wash it off first? Perhaps you wipe it off on your own clothing?

For some parents, the trick is a quick lick in their own mouths before returning it to their bawling baby.

Before you shudder at the thought, consider this. Researchers in Michigan have found that these parents may be onto something, namely the transfer of health-promoting microbes from their mouth to their child.

Previous research has shown exposure to certain microorganisms early in life through this method stimulates development of a child’s immune system. One study in Sweden showed children of pacifier-sucking parents had less eczema at 18 months.

The Michigan team interviewed mothers multiple times from six months to 18 months and found most hand-washed any dropped pacifiers. A smaller number reported sterilizing the pacifier, while 12 percent said they used their own mouths.

The study found children of parents who popped the pacifiers in their mouths had antibody levels suggesting an increased protection from allergies or allergenic asthma. The benefits began to appear at around 10 months and continued through 18 months.

The scientists noted further research is needed to determine if these benefits are from the transfer of parental microbes and if the allergy protection is sustained later in life.

One thing they stressed to those parents now considering this tactic should be obvious: Don’t do it if you’re sick.