Sputum Microbiota and the Association With Clinical Parameters in Steady-state, Acute Exacerbation and Convalescence of Bronchiectasis

Study 1 is a cross-sectional investigation. Patients with clinically stable bronchiectasis (symptoms, including cough frequency, sputum volume and purulence, within normal daily variations) will undergo baseline assessment consisting of history taking, routine sputum culture, 16srRNA pyrosequencing, measurement of sputum inflammatory markers, oxidative stress biomarkers and MMPs, and spirometry. Microbiota taxa will be compared between bronchiectasis patients and healthy subjects. In study 2, patients inform investigators upon symptom deterioration. Following diagnosis of BEs, patients will undergo the aforementioned assessments as soon as possible. This entails antibiotic treatment, with slightly modified protocol, based on British Thoracic Society guidelines \[16\]. At 1 week after completion of 14-day antibiotic therapy, patients will undergo convalescence visit. Study 3 is a prospective 1-year follow-up scheme in which patients participated in telephone or hospital visits every 3 months. For individual visit, spirometry and sputum culture will be performed, and BEs will be meticulously captured from clinical charts and history inquiry, with the final decisions adjudicated following group discussion.