RT Journal Article SR Electronic T1 The airway microbiota and exacerbations of COPD JF ERJ Open Research JO erjor FD European Respiratory Society SP 00168-2020 DO 10.1183/23120541.00168-2020 VO 6 IS 3 A1 Elise Orvedal Leiten A1 Rune Nielsen A1 Harald Gotten Wiker A1 Per Sigvald Bakke A1 Einar Marius Hjellestad Martinsen A1 Christine Drengenes A1 Solveig Tangedal A1 Gunnar Reksten Husebø A1 Tomas Mikal Lind Eagan YR 2020 UL http://openres.ersjournals.com/content/6/3/00168-2020.abstract 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