The Sciences

Spit-Cleaned Pacifiers Boost Babies' Immune Systems

D-briefBy Carrie ArnoldMay 24, 2013 8:55 PM


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The only thing a baby seems to love more than sucking on a pacifier is dropping it on the ground. Health-conscious parents often think they are doing the right thing by sterilizing the dropped binky before giving it back to their child. However new research shows that these parents might want to rethink: When parents clean a pacifier with their own saliva instead, the child is less likely to develop eczema, allergies and other related conditions. For the past century, medical science has focused on bacteria’s inherent ick factor. For some disease-causing germs like Salmonella or Staphylococcus, avoidance is probably a good thing. But the vast majority of bacteria in the environment and on our bodies are actually good for us. Numerous studies have linked the rise in autoimmune diseases like allergies, asthma, Crohn’s disease and others to our hyper-sanitized modern environments. It’s known as the hygiene hypothesis, and it states that, without exposure to a wide array of germs, our immune systems won’t learn to distinguish our own cells from harmful invaders. Having a healthy amount of germs on our hands, toys, and, yes, pacifiers is actually crucial to our overall health. To formally test this hypothesis, Bill Hesselmar and colleagues at the University of Gothenburg in Sweden tested 184 infants. When the babies were four months old, the researchers took samples of the babies’ mouth microbes. At six months, the researchers asked the parents about their pacifier cleaning habits. Then at 18 and 36 months they tested the babies for food- and airborne allergies. Those children whose parents had sucked on their dirty pacifiers to clean them had only 11% of the asthma risk as those children with binkies cleaned by other methods, the authors recently reported

in the journal Pediatrics. They also had only 27% the risk of developing eczema. Vaginal delivery (vs. caesarian section) also independently decreased risk for eczema. These decreased risks persisted until the babies turned three. The infants with spit-cleaned pacifiers also had a significantly different array of mouth microbes, which the researchers believe help explain why their allergy risks were lower. The parents’ microbes stimulated their infant’s immune system, thereby decreasing the chances of an autoimmune condition like eczema. A good reason, then, to overcome the ick. Image courtesy Ilya Andriyanov / Shutterstock

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