Figure 4.

Bacterial load is higher in periodontitis than in health, is also higher in bleeding than in non-bleeding sites and correlates with the relative abundance of specific taxa within periodontitis samples. (a) shows bacterial load measurements in periodontitis (P) in sites with bleeding (PB) or without bleeding (PnB) and in health (H). *indicates a P<0.05. To compare P and H, communities from bleeding and non-bleeding sites were combined. (b) shows taxa from periodontitis communities that showed a significant negative correlation between their relative abundance and bacterial load, while (c) shows taxa from periodontitis communities with a significant positive correlation between their relative abundance and bacterial load. Relative abundance (%) and bacterial load (number of 16S rRNA copies) data were transformed (see methods).