Sampling of the Lung Microbiome in Patients Undergoing Lung Resection

Background: Although the lung is of low biomass, it harbors a diverse and dynamic microbiome that may influence disease and healing. Existing studies have used diverse sampling methods with high propensities for contamination and sampling error, leading to diverse and unclear results. Here, we characterized the lung microbiome via airway and parenchymal samples to determine variation across patients and sampling methods. Methods: We recruited adult patients undergoing lung resection for suspected or confirmed malignancy. After resection and under sterile conditions, a 1 cm cubic piece of non-cancerous lung parenchyma and a swab from the specimen's bronchus were collected and sent for microbiome analysis via 16S rRNA gene amplicon (V4) sequencing on an Illumina platform. An established bioinformatics pipeline was used to determine taxonomic identification. Baseline clinical and demographic data were compared to microbiome composition. Results: A total of 86 patients were included in the study. Beta diversity (microbial composition) varied significantly by sampling method (biopsy of lung parenchyma versus airway swabs), so all further results were analyzed within sample types. Further analyses revealed significant differences in beta diversity by lobe of the lung, indicating a different microbial composition by anatomic location. Analyses of patient demographics revealed significant differences by age and comorbidities, including chronic obstructive pulmonary disease and atrial fibrillation. Conclusions: The lung harbors a diverse microbiome that differs by anatomic location and patient characteristics. This study provides a framework for more accurate future lung microbiome sampling and characterization.