Fig. 7From: Microbial differences between dental plaque and historic dental calculus are related to oral biofilm maturation stagePotential metabolic functional profiles differ by sample type but not health status. a SEED metabolic functional category profiles separate plaque and historic calculus in a principal component analysis. b SEED profiles of plaque and historic calculus are sufficiently discriminatory to cluster samples by type in the sparse partial least squares-discriminant analysis (sPLS-DA). c Healthy and periodontal disease site historic calculus SEED profiles overlap and are not distinctly separated by PCA. d Historic healthy and disease site calculus SEED profiles overlap and are not sufficiently discriminatory for distinct clustering by sPLS-DABack to article page