The Role of Airway Microbiota on Clinical Phenotypes and Disease Severity in Bronchiectasis

Bronchiectasis is characterized pathologically by permanent bronchial dilatation and airway inflammation, and clinically by productive cough, hemoptysis and periodic infectious exacerbations. The pathogenesis of the disease and the inflammatory, infective and molecular drivers of disease progression are not fully understood. Current available therapeutic options have shown only a modest impact on disease outcomes in randomized clinical trials. The concept of "treatable traits" was proposed as biomarker-directed approach, based on the recognition of clinical phenotype and endotypes, help to personalized treatment options. Potential treatable traits of airways disease into four broad categories: pulmonary, extra-pulmonary, etiological, and behavior and lifestyle treatable traits. Airway microbiota, including bacteria, NTM and fungus, have important but different inflammatory process in bronchiectasis. Our study will provide a new concept that airway microbiota might involve in the airway and systemic inflammation, mucus hypersecretion, as well as the airway damage, remodeling, and frequent exacerbations in bronchiectasis, thus leading to the deterioration of disease severity.

Bronchiectasis remains a major cause of respiratory morbidity and treatment is generally only partly successful. Our study will give more clues about the mechanisms by which the immunomodulatory medications (macrolides) on the inflammatory pathway and the probably different response among patients with different isolated microbiota from airways. Thus, our results will not only shed light on the airway microbiota inflammatory mechanisms responsible for disease severity, but also provide a new therapeutic direction.