Persistent airflow limitation and the airway microbiome in childhood asthma

Asthma is a major public health problem in NZ with one in four children affected. It is generally characterised by episodic reversible airway narrowing, but a significant proportion of people with asthma experience persistent airflow limitation despite optimal therapy. This is important since persistent, progressive loss of lung function in childhood may result in severe airflow obstruction and chronic obstructive pulmonary disease (COPD) in adulthood, both of which are associated with significant morbidity and mortality.

We hypothesise that lung function deficits in childhood asthma may be associated with an altered numbers or types of bacteria in the airways, and that in some types of asthma, this may be due to the interactions of bacteria with the immune system. In support of this, there is some evidence that: 1) an altered airway microbiome from infancy is associated with greater asthma risk in adulthood; 2) the airway microbiome in severe adult asthma is “disordered”; and 3) the airway microbiome is also altered in adults with COPD (another respiratory disease characterised by persistent/fixed airflow obstruction). However, little research has been conducted so far looking specifically at the airway microbiome in children.

This main aims of this study are therefore to assess the associations between the airway microbiome and persistent airflow limitation, airway hyperreactivity, severity, and airway inflammation in childhood asthma.

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