Asthma and the microbiota, how are they linked?

Asthma is a common chronic respiratory disease that affects both adults and children. Over 260 million people suffer from the disease worldwide1 and it is the most common chronic disease in children.1 Uncontrolled asthma, the most debilitating form of the disease, has serious consequences for patients’ day-to-day lives. The discovery that the gut, lung and nasal microbiota are involved in the development of asthma opens up new therapeutic avenues. Explanations below.

Created 13 October 2020
Updated 29 June 2023
Actu GP On lève le pied sur le ménage ! les poussières protègeraient contre l'asthme !

About this article

Created 13 October 2020
Updated 29 June 2023

What is asthma?

Asthma is a chronic disease of the respiratory system that manifests itself as coughing, wheezing, shortness of breath, tightness in the chest, or a combination of these symptoms.1 Symptoms are caused by a narrowing of the airways in the lungs due to inflammation of the bronchi.1 Asthma attacks occur more frequently at night or during physical activity and the severity and frequency of attacks vary from patient to patient.

Did you know that…

  • Asthma affects children more than adults. However, death from the disease is more common in adults.2
  • Childhood asthma is more common in boys, but in adulthood the disease is more common in women.2

Predispositions and triggers for asthma

Asthma is a complex multifactorial disease. It can develop due to a genetic predisposition (allergic background) and/or exposure to environmental factors such as allergens (pollens, mites), tobacco smoke or air pollution. Strong emotions, cold air or physical exercise can also trigger attacks. Lastly, individual-specific factors, such as an infection, or even obesity, can also come into play.2

Link with the microbiota?

Numerous studies note the role played by the various microbiota in the disease:

Gut microbiota

Reduced gut microbiota diversity, i.e. an imbalance in gut microbiota composition (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.   ) ), in the first years of life is associated with an increased risk of developing asthma later in childhood.3 Some researchers believe that analyzing an infant’s gut microbiota could predict the risk of developing the disease.4 One factor behind such imbalances that has received much attention is the impact of antibiotics taken in the first weeks or months of life, i.e. when the gut microbiota and immunity are developing.5 Some studies have shown a link between antibiotic use and an increased risk of asthma later in childhood.6 Moreover, one research team has recently suggested that a gut dysbiosis in infants exposed to antibiotics may be responsible for childhood asthma.7 However, this mechanism has yet to be confirmed.

Lung microbiota

The lung microbiota is also thought to play a role, and although our understanding in this area is still very limited, it is a rapidly expanding field of research.8 The discovery of a unique lung flora with signatures specific to patients suggests a role in asthma.9,10 Furthermore, it appears that respiratory function in moderate to severe asthma is associated with the degree of lung inflammation and the composition of the microbiota.11,12 While research to confirm these results is ongoing, characterizing the bacterial populations living in the lower respiratory tract may help improve patient management or even better predict attacks.10

Nasal microbiota

Data relating to the nasal microbiota are also very limited. However, an imbalance in the composition of the nasal microbiota has also been associated with the disease,13 and even with the severity of attacks,14 although no causal relationship has been established. Lastly, as with the gut microbiota, a very recent study on 700 children suggests that an alteration of the nasal microbiota due to antibiotic treatment before the age of 1 could explain the onset of childhood asthma at 7 years of age.15 However, this remains to be confirmed.

Living with asthma: treatments and solutions?

Although asthma cannot be cured, there are treatments that allow asthma patients to lead normal and active lives. Symptomatic treatments mainly limit the intensity of acute attacks by opening the bronchi, while disease-modifying treatments reduce inflammation of the airways, thus improving respiratory function and reducing attack severity.1

Studies on the relationship between the microbiota and asthma suggest that modifying the microbiota could help prevent the disease, leading researchers to focus their efforts on the use of probiotics and prebiotics.16,17 Their use as a treatment for the disease is also being studied.18

Are there any protective factors?

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. ) during early childhood seems to help prevent asthma. Contrary to popular belief, living in a sanitized environment does not necessarily protect against respiratory diseases. Some studies show that house dust is not necessarily a risk factor for the development of the disease,19 while others have shown a decreased risk of asthma in children born and raised in the countryside20 or with pets.21

This article is based on scientifically approved sources. However, if you or your child display symptoms, please consult your family doctor or pediatrician.


1 World Health Organization. 2021. Asthma. World Health Organization, Geneva, Switzerland.

2 Dharmage SC, Perret JL, Custovic A. Epidemiology of Asthma in Children and Adults. Front Pediatr. 2019 Jun 18;7:246. 

3 Abrahamsson TR, Jakobsson HE, Andersson AF, et al. Low gut microbiota diversity in early infancy precedes asthma at school age. Clin Exp Allergy. 2014 Jun;44(6):842-50. 

4 Stokholm J, Blaser MJ, Thorsen J, et al. Maturation of the gut microbiome and risk of asthma in childhood. Nat Commun. 2018 Jan 10;9(1):141. 

5 Coker MO, Juliette C. Madan JC. Chapter 3 - The microbiome and immune system development, The Developing Microbiome. Academic Press. 2020. p 43-66.

6 Murk W, Risnes KR, Bracken MB. Prenatal or early-life exposure to antibiotics and risk of childhood asthma: a systematic review. Pediatrics. 2011 Jun;127(6):1125-38. 

7 Patrick DM, Sbihi H, Dai DLY, et al. Decreasing antibiotic use, the gut microbiota, and asthma incidence in children: evidence from population-based and prospective cohort studies. Lancet Respir Med. 2020 Nov;8(11):1094-1105. 

Hauptmann M, Schaible UE. Linking microbiota and respiratory disease. FEBS Lett. 2016 Nov;590(21):3721-3738.

Millares L, Bermudo G, Pérez-Brocal V, et al. The respiratory microbiome in bronchial mucosa and secretions from severe IgE-mediated asthma patients. BMC Microbiol. 2017 Jan 19;17(1):20. 

10 Sullivan A, Hunt E, MacSharry J, et al. 'The Microbiome and the Pathophysiology of Asthma'. Respir Res. 2016 Dec 5;17(1):163. 

11 Turturice BA, McGee HS, Oliver B, et al. Atopic asthmatic immune phenotypes associated with airway microbiota and airway obstruction. PLoS One. 2017 Oct 20;12(10):e0184566.

12 Taylor SL, Leong LEX, Choo JM, et al. Inflammatory phenotypes in patients with severe asthma are associated with distinct airway microbiology. J Allergy Clin Immunol. 2018 Jan;141(1):94-103.e15. 

13 Kang HM, Kang JH. Effects of nasopharyngeal microbiota in respiratory infections and allergies. Clin Exp Pediatr. 2021 Apr 15.

14 Zhou Y, Jackson D, Bacharier LB, et al. The upper-airway microbiota and loss of asthma control among asthmatic children. Nat Commun. 2019 Dec 16;10(1):5714.

15 Toivonen L, Schuez-Havupalo L, Karppinen S, et al. Antibiotic Treatments During Infancy, Changes in Nasal Microbiota, and Asthma Development: Population-based Cohort Study. Clin Infect Dis. 2021 May 4;72(9):1546-1554. 

16 Meirlaen L, Levy EI, Vandenplas Y. Prevention and Management with Pro-, Pre and Synbiotics in Children with Asthma and Allergic Rhinitis: A Narrative Review. Nutrients. 2021 Mar 14;13(3):934. 

17 Fonseca VMB, Milani TMS, Prado R, et al. Oral administration of Saccharomyces cerevisiae UFMG A-905 prevents allergic asthma in mice. Respirology. 2017 Jul;22(5):905-912. 

18 Chiu CJ, Huang MT. Asthma in the Precision Medicine Era: Biologics and Probiotics. Int J Mol Sci. 2021 Apr 26;22(9):4528. doi: 10.3390/ijms22094528.

19 O'Connor GT, Lynch SV, Bloomberg GR, et al. Early-life home environment and risk of asthma among inner-city children. J Allergy Clin Immunol. 2018 Apr;141(4):1468-1475. 

20 Depner M, Taft DH, Kirjavainen PV, et al.  Maturation of the gut microbiome during the first year of life contributes to the protective farm effect on childhood asthma. Nat Med. 26(11):1766-1775. 2020 ;

21 Mäki, J.M., Kirjavainen, P.V., Täubel, M. et al. Associations between dog keeping and indoor dust microbiota. Sci Rep. 2021 Mar 5;11(1):5341.


    See also