PT - JOURNAL ARTICLE AU - Elise Orvedal Leiten AU - Rune Nielsen AU - Harald Gotten Wiker AU - Per Sigvald Bakke AU - Einar Marius Hjellestad Martinsen AU - Christine Drengenes AU - Solveig Tangedal AU - Gunnar Reksten Husebø AU - Tomas Mikal Lind Eagan TI - The airway microbiota and exacerbations of COPD AID - 10.1183/23120541.00168-2020 DP - 2020 Jul 01 TA - ERJ Open Research PG - 00168-2020 VI - 6 IP - 3 4099 - http://openres.ersjournals.com/content/6/3/00168-2020.short 4100 - http://openres.ersjournals.com/content/6/3/00168-2020.full SO - erjor2020 Jul 01; 6 AB - Aim The aim of this study was to investigate whether the compositionality of the lower airway microbiota predicts later exacerbation risk in persons with COPD in a cohort study.Materials and methods We collected lower airways microbiota samples by bronchoalveolar lavage and protected specimen brushes, and oral wash samples from 122 participants with COPD. Bacterial DNA was extracted from all samples, before we sequenced the V3-V4 region of the 16S RNA gene. The frequency of moderate and severe COPD exacerbations was surveyed in telephone interviews and in a follow-up visit. Compositional taxonomy and α and β diversity were compared between participants with and without later exacerbations.Results The four most abundant phyla were Firmicutes, Bacteroidetes, Proteobacteria and Fusobacteria in both groups, and the four most abundant genera were Streptococcus, Veillonella, Prevotella and Gemella. The relative abundances of different taxa showed a large variation between samples and individuals, and no statistically significant difference of either compositional taxonomy, or α or β diversity could be found between participants with and without COPD exacerbations within follow-up.Conclusion The findings from the current study indicate that individual differences in the lower airway microbiota in persons with COPD far outweigh group differences between frequent and nonfrequent COPD exacerbators, and that the compositionality of the microbiota is so complex as to present large challenges for use as a biomarker of later exacerbations.Contrary to previous reports, in this study there were no significant associations between the lung microbiota in stable COPD and COPD exacerbation frequency https://bit.ly/2ZVcNdG