Figure 2. Core OTUs present in at least seven of the nine oral sites.

While each 16S amplification (V1–V3 and V3–V5) has 6 core OTUs, there are differences between the amplifications, with Pasteurellaceae and Lactobacillales identified with the V3–V5 tags but not the V1–V3 tags, and Leptotrichia and Granulicatella (a member of the Lactobacillales order) identified with the V1–V3 tags but not the V3–V5 tags. Fucobacterium, Gemella, Streptococcus, and Veillonella were identified in both sets of OTUs.