Sharing your baby’s binky can be good for their health

Here’s a quick quiz:

Your baby drops her pacifier on the floor.

Do you:

1. Wash it thoroughly with hot water and soap before giving it back?
2. Wipe it on your sleeve, then give it back?
3. Pop it into your own mouth for a quick rinse?
4. Drop it right into the trash can?

According to a new Swedish study, the surprising answer may be “c.”

Published in this week’s journal Pediatrics, researchers at the Sahlgrenska Academy of Göteborg University followed 184 babies and their parents, testing the tots for several conditions, including allergies, eczema and asthma. Additionally, the researchers asked parents how they cleaned off their baby’s pacifiers. Almost half said they used their own mouths, on occasion.

By the time the babies reached 18 months, those whose parents sucked their pacifiers clean were found less likely to have allergies, asthma and, particularly, eczema. According to the conclusions, this decrease in susceptibility comes from exposure babies received to bacteria in their parents’ saliva, which stimulated their immune systems for better protection.

Analysis of the babies’ saliva showed patterns that suggested the introduction of microbes from the parents’ saliva had altered the microbes in their child’s mouths, researchers found.

According to Dr. Ayesha Siddiqi, pediatric allergist and immunologist at Advocate Illinois Masonic Medical Center, Chicago, this supports what’s known as the “hygiene hypothesis.”

“According to the theory, children in developed nations aren’t exposed to as many germs as they used to be,” Dr. Siddiqi says. “With cleansers and constant hand-washing, we’ve created much more sterile environments for our children.”

Dr. Siddiqi says because of all this sterility, children may not develop the immunity and other natural defenses their bodies need to fight off conditions, including allergies. By licking the pacifiers themselves they’re exposing their babies to common bacteria in their own mouths, thus allowing their bodies the chance to mount an early defense.

Though she agrees with the theory in principle, Dr. Siddiqi says she would not recommend licking a baby’s pacifier and giving it back to them as a common practice.

“Parents may have infections themselves that they are unaware of and may expose their baby to those infections,” she says. “They may unknowingly pass on something that’s not easily treated in young children.”

Plus, if they’re not careful, parents may unwittingly expose themselves to harmful bacteria, depending on where the pacifier dropped.

“Exposure to some germs is OK, so this theory makes some sense,” she says. “We don’t have to be overly clean all the time.”