Fig. 4

Relative abundance of bacterial taxa associated with the azithromycin (AZ)-treated vs. non-AZ-treated samples. Legend: The relative abundance refers to how common or rare a species is relative to other species in the oropharyngeal microbiome of the entire sample population (n = 44). Supervised (machine) learning with definition by randomForest and confirmation by Boruta feature selection (at cut off-value 25) enabled visualization of bacterial taxa associated with the AZ-treated (visits V3 and V6, n = 16) vs. non-AZ-treated samples (visit V2 from all samples and placebo samples, n = 28). The list is sorted first by Mann–Whitney U score followed by the largest disparity in medians between the No treatment group and the Treatment group. Taxa represent the lowest taxonomic depth that is labeled by RDP Classifier (at ≥ 80% bootstrap cut off). Boxes represent the first quartile, median, and third quartile of the distribution of OTUs for each treatment group. Empty circles represent outliers that are 1.5x greater than the respective interquartile ranges. The species level identification of the Boruta feature selection results were obtained through The Human Oral Microbiome Database (HOMD) Blast Search Tool