Examples of community classes of human body habitats as illustrated by PCoA. PCoA was used to visualize the community classes in different habitats. Samples are color-coded according to their community classes within the habitat. Only the major community classes from retroauricular crease are colored. The community classes show better separation in retroauricular crease and vaginal sites with higher silhouette values, and a less clear separation in stool and anterior nares with lower silhouette values.