Relationship between the microbiome and the GOLD Stage during exacerbations

Introduction: Increasing evidence suggests that the lung microbiota is crucial in chronic obstructive pulmonary disease (COPD). The main goal was to observe diversity, composition and microbial patterns in COPD sputum samples, clustered by GOLD stage. Methods: An observational study of 26 COPD patients during acute exacerbation (AEPOC) was conducted. DNA sputum samples were isolated and it was sequenced using Illumina MiSeq platform. Data was clustered according to GOLD ABCD and GOLD 1,2,3 vs. 4. Results: Alpha diversity was lower in GOLD B and D. This difference was significant for Shannon diversity and inverse Simpson’s Index (Fig.1A). Principal coordinate analysis (PCoA) showed that GOLD B and D had an increased in NMSD2 in compare to GOLD A and C, indicating compositional differences in beta diversity (Fig.1B). Linear discriminant analysis effect size (LefSE) analysis revealed that Haemophilus had dominance at the genus level in GOLD 4 (Fig. 1C). In contrast, bacterial communities presented more differences in GOLD 1-3. Conclusion: GOLD B and D (i.e. symptomatic patients) wereassociated with a significant decrease in richness, and increased abundance of taxa, defined by alfa and beta diversity, respectively. Moreover, the LDA score revealed differences in bacterial composition between GOLD 1-3 vs. GOLD 4, with a repeated pattern of Haemophilus genus dominance in GOLD 4 patients.