Can parents pass healthy bacteria to their babies by sucking on their pacifiers? New research suggests that parents who cleaned their babies’ pacifiers by sucking on it actually helps their children to prevent having allergic reactions.

Cleaning Pacifiers

A study being presented at the American College of Allergy, Asthma, and Immunology meeting in Seattle focuses on something parents of young children do everyday: clean pacifiers. In the study, researchers theorized that by cleaning the pacifiers by sucking on it, the parents are able to pass on health oral bacteria in their saliva to their young children, thereby helping the development of their immune systems.

To conduct the study, researchers interviewed 128 mothers who were asked how they cleaned their children’s pacifiers, whether they sterilized it, washed with soap and water, or sucked on it. Of the lot, 30 mothers sterilized the pacifiers while 53 cleaned it with soap and water, and nine sucked on it.

Immunoglobin E

The researchers then compared the infants’ Immunoglobulin E (IgE) levels at birth, at six months, and at 18 months for each cleaning method, and found that the infants whose mothers sucked on their pacifiers had significantly lower IgE levels at 18 months, with the differences beginning to show at 10 months.

IgE is a type of antibody that is related to the development of allergic responses in the body. Although there are certain exceptions, higher IgE levels are typically associated with higher risks for developing allergies and allergic asthma.

Immune System Development

The study is the first of its kind in the United States to study pacifier cleaning methods and IgE, but its results run similar to the results of a 2013 Swedish study, which also found a link between parental sucking on baby’s pacifier, and reduced risk in allergy development.

That said, the researchers are not advising parents to suck on their babies’ pacifiers, as more research in needed to truly examine the correlation.

“Although we can't say there's a cause and effect relationship, we can say the microbes a child is exposed to early on in life will affect their immune system development,” said study lead Eliane Abou-Jaoude, M.D.

The study was funded by the Henry Ford Health System.