The Barwon Infant Study compared dummy use and cleaning methods among infants at six months of age and those with a confirmed food allergy at one year of age in more than 700 participants in Geelong.
The research, published in the Journal of Allergy and Clinical Immunology, found infants whose dummies were sterilised with an antiseptic solution were more likely to have a diagnosed food allergy at the age of one.
Centre of Food and Allergy Research investigator and Murdoch Children’s Research Institute Ph.D. candidate Victoria Soriano said the link between dummy sterilisation and food allergies warranted further research into how good bacteria in the infant mouth and gut could help prevent food allergies.
“These findings support the growing recognition of the importance of good bacteria, known as ‘microbiome’, in our mouth and gut on healthy growth and development,” Ms Soriano said.
The research found no increase in risk of food allergy at one year of age among dummy users when the dummies were washed in tap water, boiling water, put in the parent’s own mouth, or not washed at all before being given to infants at six months of age.
“This research should not discourage the cleaning of dummies, as this is a vital step in keeping a child safe from the more immediate risk of infectious diseases,” Ms Soriano said.
“There is also no evidence from this study that cleaning dummies by other methods is harmful.”
The study team has contacted the Royal Australasian College of Physicians who are further considering this issue.
Food allergy (FA) is a serious disease that can cause life-threatening anaphylaxis due to an immune-mediated reaction to food proteins. FAs commence in infancy, but prevention methods are still not well understood. Maternal and infant gut microbiome have been repeatedly studied in relation to immune regulation and susceptibility to allergic disease. Prenatal pet exposure has been shown to influence differentiation of regulatory T immune cells in utero.1,2
Prevotella copri in maternal gut microbiota during pregnancy is associated with decreased likelihood of allergic disease in the infant.3 Early-life gut microbiota have been reported to suppress IgE production and, in mouse models, linked to resistance to FA.4,5 Various microbial exposures, including vaginal births, siblings, dog ownership, and infant antibiotics, have been associated with a decreased risk of FA.6, 7, 8 Little is known about the relationship between oral microbial exposures, local immune mechanisms of tolerance induction, and IgE-mediated FA.
Pacifiers (also known as dummies or soothers), commonly used in infancy and recommended in the United States,9,10 are another source of microbial exposure in early life.9, 10, 11 A Swedish birth cohort found potential benefits of shared microbial exposure as infants whose parents sucked their pacifier (ie, used their own mouth to clean it) had reduced food sensitization, asthma, and eczema at 18 months compared with infants whose parents used other cleaning methods.12
Another cohort study identified lower total IgE levels in children from 10 to 18 months if mothers reported sucking the infants’ pacifier (n = 9 of 74) at 6 months compared with not sucking their pacifier.13
Despite most infant pacifiers being cleaned in some way, no previous work has finely classified pacifier use in the context of the associated cleaning method (sanitization), nor has challenge-proven FA been examined.
Here, we define “pacifier sanitization” as the joint exposure of a pacifier and a specific cleaning method (eg, tap water and chemical antiseptic). The Barwon Infant Study (BIS) is a population-based cohort study of 1074 infants that measured FA outcomes.3,14,15 We aimed to investigate combinations of infant pacifier sanitization in the first year of life in association with FA prevalence at age 1 year.
reference link : https://www.jacionline.org/article/S0091-6749(21)00221-9/fulltext
More information: Victoria X. Soriano et al. Infant pacifier sanitization and risk of challenge-proven food allergy: A cohort study, Journal of Allergy and Clinical Immunology (2021). DOI: 10.1016/j.jaci.2021.01.032
