Current status of microbiome research in asthma and chronic obstructive pulmonary disease

ABSTRACT

Asthma and chronic obstructive pulmonary disease (COPD) are characterized by chronic airway inflammation resulting in airflow limitation. They include various phenotypes and endotypes in their disease entities. For that reason, they lack proper biomarkers and epoch-making progresses in treatment nowadays. Healthy airway has been believed to be sterile traditionally. However, with the help of nonculture sequencing techniques, researchers discovered that it is full of the commensal and symbiotic microbial flora. Therefore, microbiome has emerged as a possible biomarker and a clue to understand the pathogenesis of airway disease. Microbiome research in asthma has focused on the association between characteristics of microbiome, such as composition and diversity. However, now it refers to the role of microbiome, including Proteobacteria, in the development and pathogenesis of asthma and allergic diseases. Microbiome research in COPD has revealed its different composition according to the existence and severity of the disease. Also, differences in microbiome composition according to exacerbation state or specific treatment of COPD are reported. Therefore, many researchers pay attention to the possible role of microbiome as a biomarker or a treatment target in asthma and COPD. Herein, we review recent studies on microbiome research in asthma and COPD.