Overview: Members of the genus Tannerella are moderately abundant in the oral microbiome, making up less than 0.5% on average of the microbiome at any oral site. They are close relatives of the genus Porphyromonas and are classified with them into the family Porphyromonadaceae.

Ecological role/importance in health and disease: Tannerella spp. are found primarily in sub- and supragingival dental plaque and in samples from the tonsils and throat. Tannerella forsythia (formerly T. forsythensis), together with Porphyromonas gingivalis and Treponema denticola, is part of the "red complex" of subgingival taxa associated with periodontitis (Socransky et al. 1998). The other members of genus Tannerella in HOMD have not yet been named.