[Asthma and the microbiome]

It has been demonstrated recently that the respiratory tract, considered for a long time to be sterile in the healthy subject, contains a vast community of bacteria called the respiratory microbiome. This microbiome, like the intestinal microbiome, is in constant interaction with the immune system of the human host. This relationship has allowed us to formulate some new theories on the pathophysiology of asthma.

The respiratory microbiome of the asthmatic differs quantitatively and qualitatively from that of the healthy subject. Equally there seem to be differences in the microbiome according to the degree of severity of the asthma and the response to treatment with corticosteroids. It has been shown in murine models of allergic asthma that an early disturbance of the microbiome by different perinatal factors could be responsible for disorders of the development of the immune system, leading to the development of asthma in the long term.

As a disorder of the microbiome might be implicated in the pathophysiology of asthma, the maintenance or restoration of a healthy microbiome is emerging as a possible new strategy in the management of the disease.

The implication of the microbiome in the pathogenesis of human asthma seems to be more and more likely. This could have possible therapeutic implications, notably the restoration of a healthy microbiome.