A Study About Association Between Microbiome, Metabolome and Clinical Characteristics in COPD Patients

brief summary

The goal of this observational registry study is to compare characteristics of gut and sputum microbiome and metabolome among COPD patients with significant smoking history, COPD patients without significant smoking history and healthy smoker. Additionally, the investigators investigate the difference of blood metabolites and peripheral blood mononuclear cells level among groups. The main questions it aims to answer are: * Are there significant difference in fecal or sputum microbiome and metabolome between COPD patients and healthy smoker? * Are there any distinct characteristics in microbiome and metabolome in COPD with COPD patients with significant smoking history, COPD patients without significant smoking history compared with healthy smoker? * Are there any difference in blood metabolites and peripheral blood mononuclear cells levels among patients with significant smoking history, COPD patients without significant smoking history and healthy smoker * Might distinct characteristics of microbiome and metabolites in COPD patients be related to worse clinical outcomes in COPD patients?