Many parents probably think nothing of sucking on their baby's pacifier to clean it after it falls to the ground.
While more research is needed, and experts caution parents not to conclude that sucking on the pacifier is a sure way to prevent the development of allergies or asthma in their child, the study suggests babies may receive "healthy oral bacteria that will affect the early development of their child's immune system" when a pacifier is cleaned in this way.
The study is being presented at the American College of Allergy, Asthma and Immunology meeting in Seattle.
According to new USA research being presented at the American College of Allergy, Asthma and Immunology (ACAAI), the children of mothers who sucked on their pacifiers in order to clean them had a lower allergic response than children whose mothers cleaned the soothers either by sterilization or hand washing. IgE is linked to the development of allergies and asthma. Of those 128, 53 said they cleaned it with soap and water, 30 said they sterilized it either using the dishwasher or boiling water, while nine said they sucked on the pacifier to clean it.
Dr. Edward Zoratti, a co-author of the study and an allergist-immunologist at Henry Ford Health System, said the suppressed levels of IgE were evident in the babies at around 10 months of age until they were 18 months old. At that time, researchers in Sweden also concluded the "parental sucking of their infant's pacifier may reduce the risk of allergy development, possibly via immune stimulation by microbes transferred to the infant via the parent's saliva".
"We found the children of mothers who sucked on the pacifier had lower IgE [immunoglubin E] levels", Dr. Eliane Abou-Jaoude, the study's lead author and a fellow at the Henry Ford Health System in Detroit, explained in a press release.
Additional analyses indicated the differences were first seen at about 10 months, researchers said.
"Our study indicates an association between parents who suck on their child's pacifier and children with lower IgE levels but does not necessarily mean that pacifier sucking causes lower IgE", Abou-Jaoude said.