Fig. 6

Biotyping clusters of COPD sputum microbiota at stable, acute exacerbation and follow-up visits. For each state, optimal cluster number analysis using the Calinski-Harabasz index, scatter diagram of samples clustered by between-class principal component analysis, contribution of major bacterial genera in means per class and proportion of samples belonging to each cluster plotted by region, frequency of exacerbation, frequency of of viral exacerbations, antibiotics use, corticosteroids use and CODP duration are presented at stable (a), acute exacerbated (b) and exacerbated follow-up visits (c)