The characterization of lung microbiome in lung cancer patients with different clinicopathology

There were few knowledge concerned correlation between lung microbiome and different clinicopathology of lung cancer. Bronchial washing fluid (BWF) and sputum are commonly used sample types but there was no study comparing difference of microbiome between these two in lung cancer. In this study, we aimed to compare difference of microbiome between these two sample types and characterize lung microbiome in squamous cell lung carcinoma with (SCC_M1) or without distant metastasis (SCC_M0) and lung adenocarcinoma with (AD_M1) or without distant metastasis (AD_M0). We collected 40 BWF samples and 52 sputum samples from newly diagnosed lung cancer patients. Bacterial species were sequenced via 16S rRNA sequencing. Phylum Proteobacteria in BWF samples were significantly higher than sputum samples (Wilcoxon test, P = 0.003). At phylum level, microbiome of BWF samples was more similar to that of lung cancer tissues reported in the previous literature. LEFse analysis showed that in BWF group, genera Veillonell, Megasphaera, Actinomyces and Arthrobacter in AD_M0 were significantly higher than those in SCC_M0, and genera Capnocytophaga and Rothia in AD_M1 were significantly lower than that in SCC_M1. Compared with AD_M0, genus Streptococcus of AD_M1 was significantly lower, and genera Veillonella and Rothia in SCC_M1 were significantly higher than that in SCC_M1. Our study suggested that BWF samples might better reflect the microbiome of lung cancer tissues. In different metastatic states of lung cancer, differential genera between squamous cell carcinoma and adenocarcinoma were different. And in different histologic types of lung cancer, distant metastasis-related genera were not the same.