What could prevent my child’s respiratory allergies?
Itching, tingling, a runny nose, watery eyes… Every year, the arrival of spring and its high pollen levels indicate that allergic rhinitis is back with a bang. The most common and the most persistent manifestation of respiratory allergy, allergic rhinitis blights the lives of 40% of the global population.1 This particularly complex respiratory disorder results from several genetic and environmental factors, including an imbalance of the gut and ENT microbiota.
Parents, take hope, there are also protective factors.
So how can your child's respiratory allergies be prevented?
About this article
Microbiota and allergic rhinitis: what is the link?
The symptoms of rhinitis are caused by an overreaction of the immune system to allergens. Allergic rhinitis is described as seasonal (the notorious “hay fever”) when it is linked to the pollen of grasses, trees or herbaceous plants. It is described as perennial when it is caused by allergens present throughout the year (dust mites, animal hairs, molds).2
40% Allergic rhinitis is thought to affect up to 40% of the global population with a high prevalence
This disease is associated with an imbalance of the ENT microbiota (ear-nose-throat) and of the gut microbiota, also known as “ (sidenote: Dysbiosis Generally defined as an alteration in the composition and function of the microbiota caused by a combination of environmental and individual-specific factors. Levy M, Kolodziejczyk AA, Thaiss CA, et al. Dysbiosis and the immune system. Nat Rev Immunol. 2017;17(4):219-232. ) ”.
Some studies report disparities in the composition of the gut microbiota between people suffering from acute episodes of seasonal allergic rhinitis and non-allergic individuals.3 One study in children4 reveals that the diversity of the nasal microbiota is reduced when they are suffering from rhinitis, with a specific bacterial signature that reflects the respiratory disease and its severity level.
Gut microbiota: still many things to be discovered
Protective factors against allergic rhinitis?
It would seem that exposure to (sidenote: Microorganisms Living organisms that are too small to be seen with the naked eye. They include bacteria, viruses, fungi, archaea and protozoa, and are commonly referred to as “microbes”. What is microbiology? Microbiology Society. ) in early childhood is beneficial for the prevention of allergies. Contrary to received ideas, living in an aseptic environment does not necessarily offer protection.
In fact, some studies report that house dust might protect against allergies.5Living in the countryside is also thought to be beneficial, thanks to the farming environment that suppposedly shapes the development of the gut microbiota.6 Finally, living with others also has its benefits and may prevent the occurrence of the allergy: researchers have thus observed that in children without siblings attending a kindergarten, there is a significantly reduced risk of allergic rhinitis, compared to children without siblings who are kept at home.7 Faced with allergic rhinitis, hurrah for large families!
The importance of the first 1000 days of life
This period from conception to 2 years of age is critical for infant growth and development.8 In fact, it is during this time window that colonization of the gut microbiota begins and that the immune system starts to develop and mature.
Antibiotics, delivery method, diet... all these factors that impact and destabilize the gut microbiota can have long-term effects on susceptibility to disease (allergic rhinitis among many others).9
1 Yuan Y., Wang C., Wang Q., et al. Airway Microbiome and Serum Metabolomics Analysis Identify Differential Candidate Biomarkers in Allergic Rhinitis. Front Immunol. 2022 Jan 5;12:771136
2 Nur Husna SM, Tan HT, Md Shukri N, et al. Allergic Rhinitis: A Clinical and Pathophysiological Overview. Front Med (Lausanne). 2022 Apr 7;9:874114.
3 Yuan Y., Wang C., Wang Q., et al. Airway Microbiome and Serum Metabolomics Analysis Identify Differential Candidate Biomarkers in Allergic Rhinitis. Front Immunol. 2022 Jan 5;12:771136
4 Ta L. D., Yap G. C. et al, Establishment of the nasal microbiota in the first 18 months of life: Correlation with early-onset rhinitis and wheezing. J Allergy Clin Immunol 2018
5 Hyytiäinen H, Kirjavainen PV, Täubel M, et al. Microbial diversity in homes and the risk of allergic rhinitis and inhalant atopy in two European birth cohorts. Environ Res. 2021 May;196:110835.
6 Jackson CM, Mahmood MM, Järvinen KM. Farming lifestyle and human milk: Modulation of the infant microbiome and protection against allergy. Acta Paediatr. 2022 Jan;111(1):54-58.
7 Svanes C, Jarvis D, Chinn S, et al. European Community Respiratory Health Survey. Early exposure to children in family and day care as related to adult asthma and hay fever: results from the European Community Respiratory Health Survey. Thorax. 2002 Nov;57(11):945-50.
8 Aires J. First 1000 Days of Life: Consequences of Antibiotics on Gut Microbiota. Front Microbiol. 2021 May 19;12:681427.
9 Kalbermatter C, Fernandez Trigo N, Christensen S, et al. Maternal Microbiota, Early Life Colonization and Breast Milk Drive Immune Development in the Newborn. Front Immunol. 2021 May 13;12:683022.