Fig. 3

The distribution of phyla across all four groups is shown. By Kruskal-Wallis tests, there were significant differences between the groups in Bacteroidetes (p = 0.0031), Proteobacteria (p = 0.0013), and Firmicutes (p = 0.0017). Post-hoc tests by Dunn’s Multiple Comparison method demonstrated that the differences observed in Bacteroidetes and Proteobacteria were driven entirely by the difference between the HIV + COPD- and HIV-COPD- groups. However, the difference observed in Firmicutes was driven by the difference between the HIV + COPD+ and HIV-COPD+ groups. There were no significant differences in phyla distribution between the COPD+ and COPD- groups