Quantitative PCR-derived relative abundance of indicator organisms. Data for indicators are presented as reciprocals of the mean normalized cycle threshold (Ct) values (that is, Ctindicator species/Cttotal bacteria). Individual points represent average normalized expression values for each individual based on duplicate runs in both health (solid circles) and CP (inverted open triangles) for (A) Total bacterial load. (B) Filifactor alocis, (C) Porphyromonas gingivalis, and (D) Tannerella forsythia. Significant differences between healthy cohorts and those with chronic periodontitis within each of the respective locations in the oral cavity is based on non-parametric Mann-Whitney Test with outliers removed using Grubbs’ Outlier Test. *0.01 < P < 0.05; **0.001 < P < 0.01; ***P < 0.001; ****P < 0.0001.