After the introduction of the gut-lung axis theory, extensive studies revealed the diversity of microbiomes among healthy smokers and COPD patients form the respiratory samples or lung tissues. In the previous study, distinct difference in composition of microbiome in lung tissue between healthy smokers and COPD patients was reported. This study is to build a microbiome cohort by collecting sputum and fecal samples every few months for three years from healthy smokers and chronic obstructive pulmonary disease (COPD) patients who are being followed up by Asan Medical Center. The aim of this study is to analyze the composition of microbiome of various samples (e.g. sputum, feces) and describe the difference between healthy smokers and COPD patients. This study would help establishing gut-lung axis model in humans.
