“… 1 , 2 Microbiota changes also occur in the lower airways of asthma, especially severe asthma, 3 obese asthma, 4 or asthma complicated by bronchiectasis. 5 , 6 Another phenotype of airway disease that should be discussed for microbiota changes may be asthma and COPD overlap (ACO). Patients with ACO often experience more severe conditions than those with each disease alone and are at risk of bacterial infection.…”