Principal coordinate analysis (PCoA) plot with Bray-Curtis dissimilarity. Results revealed that tongue samples clustered separately from tooth samples (SubG and SupG), suggesting that the tongue community is relatively unique from that in SupG and SubG sites. No obvious clustering was apparent within or between SupG and SubG samples. (A) Bray-Curtis PCoA ordination of pooled SupG, SubG, and tongue samples. (B) Ordination of SubG samples. Healthy patient samples are shown in green, diseased patient samples in pale red. (C) Ordination of SupG samples. (D) Ordination of tongue samples.