Dummies and Food Allergies…What is the link?
A recent study has established a link between the use of antiseptic agents to clean dummies (also known as pacifiers or soothers) and an increase in the prevalence of food allergies. In the current ‘Covid climate’ we are living through, where hand sanitiser and antiseptic wipes have become the must-have item in every handbag, it might be easy to assume that 'the cleaner the better’ when it comes to what goes into your baby’s mouth, but what does the science say?
The Infant Microbiome and the Immune System
An association between the infant gut and oral microbiota and the likelihood of developing a food allergy has been demonstrated in a growing body of evidence. (1) We know that the first couple of years of life are extremely important in the development of a healthy microbial population, influenced via various environmental exposures. Certain microbial species have been shown to reduce or promote inflammatory states, shaping aspects of the immune system, and influencing the development of allergic disease. (1)
Food Allergy
Food allergy is one of the most common forms of allergic disease in children, particularly in developed countries. (2) Although the exact reasons are undefined as to why some children develop food allergies, whilst others don’t, current knowledge suggests that food allergy development is likely influenced by interactions between the epigenome, genome, and environment, which then leads to changes in immune function. (2) These changes to the infant’s immune system may then present as food allergy, eczema, or asthma.
Factors Influencing Likelihood of Infant Food Allergy Development.
Although there is still no consensus on the best way to prevent a food allergy developing in infancy, there are certain environmental factors that are thought to influence the probability.
The presence of Prevotella copri in maternal gut.
Having siblings
Vaginal birth
Infant feeding practices
Owning a pet
Infant antibiotics (1, 2)
Dummies and the Microbiome
Dummies are yet another source of microbial exposure during infancy. Various dummy cleaning methods have been studied for their potential effect on the infant microbial population. Popular methods of cleaning dummies include parents sucking the dummy, soaking in boiling water, washing with tap water, or using an antiseptic agent. (1)
Interestingly, studies have shown that the infants whose parents suck the dummy to clean it are less likely to develop food sensitisation, eczema, or asthma by 18 months, when compared to other cleaning methods. (3)
A mentioned above, one very recent study from 2021 found that using an antiseptic cleaning agent to clean the dummy was associated with an increased prevalence of food allergies in infants when compared to boiling the dummy, rinsing in tap water, or parents sucking the dummy. (1)
Technically, both using an antiseptic agent, and boiling the dummy, should effectively sterilise the dummy, resulting in less foreign microbes entering the infant’s mouth than other cleaning methods. Interestingly, however, results between these two methods of sterilisation (antiseptic vs. boiling) differed greatly, with no increase in the prevalence of food allergy for those who had the boiled dummies. (1)
There are a few plausible explanations for this:
One hypothesis is that parents in the study were merely rinsing the dummies with previously boiled water, rather than boiling the dummy in the water for 3-5 mins, as would be required to completely sterilise, thereby introducing more microbes to the infant than they would otherwise.
The chemicals in the antiseptic may be altering the oral microbial flora, thereby altering immune regulation and increasing likelihood of developing allergic disease.
The antiseptic may be increasing the leaching of plasticisers from the dummies, resulting in greater exposure to the infant, which has been associated with increased risk of food allergy. (1)
Although this particular study can not conclusively explain the mechanism via which antiseptic use for dummies and an increase in food allergy prevalence is associated, it does highlight the importance of future research in this area. It also raises questions surrounding the recommended sterilisation techniques for dummies, which are, as of yet, unspecified.
Other studies have noted a link between the use of antiseptic cleaners and gut microbiome dysbiosis, which has been associated with an increased risk of food allergy. (2) We know that our gut microbiota function and structure, plus any alterations in the gut population, plays a pivotal role in the development of allergic disease. (2, 4)
In conclusion, the results of this 2021 study on antiseptics and dummies, combined with our knowledge so far on the potential negative impact of antiseptic agents on the infant gut and oral microbiome, suggests that finding alternative methods of cleaning our infant’s dummies may be a safer option to reduce the likelihood of food allergy development.
References
1. Soriano VX, Koplin JJ, Forrester M, Peters RL, O’Hely M, Dharmage SC, Wright R, Ranganathan S, Burgner D, Thompson K, Dwyer T. Infant pacifier sanitization and risk of challenge-proven food allergy: A cohort study. Journal of Allergy and Clinical Immunology. 2021 Mar 30.
2. Berni Canani R, Paparo L, Nocerino R, Di Scala C, Della Gatta G, Maddalena Y, Buono A, Bruno C, Voto L, Ercolini D. Gut microbiome as target for innovative strategies against food allergy. Frontiers in immunology. 2019 Feb 15;10:191.
3. Hesselmar B, Sjöberg F, Saalman R, Åberg N, Adlerberth I, Wold AE. Pacifier cleaning practices and risk of allergy development. Pediatrics. 2013 Jun 1;131(6):e1829-37.
4. Aitoro R, Paparo L, Amoroso A, Di Costanzo M, Cosenza L, Granata V, Di Scala C, Nocerino R, Trinchese G, Montella M, Ercolini D. Gut microbiota as a target for preventive and therapeutic intervention against food allergy. Nutrients. 2017 Jul;9(7):672.
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