If you clean your baby’s pacifier by sucking it, you may well be reducing your infant’s risk of developing allergies, researchers from the University of Gothenburg, Sweden, reported in the journal Pediatrics (May 6th, 2013 issue).

Exposing a baby’s immune system to microbes which benefit from the host, but have no detrimental effects on that host (commensal microbes), may protect against the development of allergy.

Microbes in our mouths may be transferred to our infants via pacifiers. Bill Hesselmar and team set out to determine whether pacifier cleaning practices might affect allergy development in infants.

The team examined 184 infants for clinical allergy and sensitization to food and airborne allergens when they were 18 months and three years of age.

They also gathered and examined data on parents’ pacifier cleaning practices. All parents were interviewed when their infants were six months old. Infant saliva samples were collected when they were 4 months old.

The infants of the 65 parents who cleaned their pacifiers by sucking them…

  • were less likely to develop asthma
  • were one third less likely to develop eczema

The authors added that babies who were delivered vaginally were also less likely to develop eczema – “vaginal delivery and parental pacifier sucking yielded independent additive protective effects against eczema development.”

The researchers also found that at four months, the salivary microbiota of infants whose parents sucked their pacifiers clean were different from the microbiota found in the saliva of the other babies.

The authors concluded:

“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.”

Dr. Hesselmar added that when babies start eating solid foods does not seem to affect their risk of developing allergies.

If parents were to read all the studies carried out on pacifiers they would probably have no idea what to do. Some studies praise pacifier usage while others warn of hazards and harms.

Researchers from the University of Wisconsin-Madison warned in Basic and Applied Social Psychology (September 2012 issue) that pacifiers might damage the emotional development of baby boys. Their study found that pacifiers stop babies from experimenting with facial expressions at a very young age.

Another study, carried out by a team from Oregon Health & Science University found that babies who are not given pacifiers while in hospital are more likely to drink more formula, which in turn may reduce their likelihood of being fed breast milk.

Written by Christian Nordqvist