Fig. 5. Effect of nitrate and Rothia aeria supplementation on in vitro periodontal biofilm composition.

Bacterial composition of periodontal plaque biofilms grown in vitro supplemented with or without 5 mM nitrate and Ra9 (n = 11). A Relative abundance at species taxonomic level as determined by 16 S rRNA gene sequencing. The top 20 most abundant species are shown and sorted by overall mean abundance; all other species are included as “other”. B Log2 fold-change of relative abundance of all species showing significant changes (ANCOM-BC adjusted p-value < 0.05). Species identified by the Boruta method as a significantly relevant feature are marked (#). C Box and whisker plot of the dysbiosis index. The dysbiosis index is expressed as SMDI score¹². Plotted are the median, 25th to 75th percentile (box) and lowest to highest value (whiskers). Differences are not statistically significant (adjusted p-value > 0.05 according to Wilcoxon matched-pairs signed rank test). Ra9: Rothia aeria CECT9999.