Multi-site microbiomes' response to chronic obstructive pulmonary disease

This study aimed to evaluate the changes of oral, nasal, pulmonary, and gut microbiota in chronic obstructive pulmonary diseases (COPD) patients and explore their interrelationships compared to the healthy group. This study included 32 COPD patients and 29 healthy individuals. A total of 162 orals, nasal, sputum, and fecal samples were obtained. The microbiota was determined by full-length 16S rDNA gene sequencing based on the PacBio sequencing platform. In sputum and stool specimens, alpha and beta diversity were significantly decreased in COPD patients. The Bray-Curtis distance indicates an overlap in microbial flora between the oral cavity and sputum, distinctly separated from nasal and fecal microorganisms. Haemophilus haemolyticus and Haemophilus parahaemolyticus were biomarkers for COPD group in sputum. The IL-6 was negatively correlated with Neisseria subflava in the oral cavity samples, and with the Porphyromonas endodontalis, Neisseria macacae, Prevotella intermedia in the sputum samples, with butyrate-producing bacteria in the fecal samples. The bacterial key nodes of sputum from COPD patients were mainly composed of low-abundance bacterial genera. The microbiome of the lungs originates from the oral microbiome, but it can be changed by the COPD. The lung microbiome is still more sensitive and accurate than the oral, nasal, and fecal microbiomes in COPD. Low-abundance taxa in the lung may be the key flora contributing to the development of COPD.