Fig. 1

Shannon Diversity Index differences between (a) COPD + and COPD− groups, (b) HIV + and HIV− groups, and (c) COPD + HIV + , COPD + HIV−, COPD−HIV + and COPD−HIV− groups. The COPD + HIV + group featured the lowest Shannon Diversity Index of all four groups. P-values were adjusted for age, sex, and smoking status. Microbial community structures in AECs according to (d) COPD status (COPD− (N): red circles; COPD + (Y): blue circles), (e HIV status (HIV− (Negative): red circles; HIV + (Positive): blue circles), and (f) combined COPD + HIV status (COPD + HIV +: purple circles; COPD + HIV−: blue circles; COPD-HIV +: green circles; COPD−HIV−: red circles) based on Bray–Curtis distances; the centroids for each group are also shown. Permutational multivariate ANOVA (PERMANOVA) was used for comparisons of microbial community structures between groups, with adjustment for age, sex, and smoking status