In Situ Intraepithelial Localizations of Opportunistic Pathogens, Porphyromonas gingivalis and Filifactor alocis, in Human Gingiva

•The gingival epithelium serves as a growth reservoir for opportunistic bacteria.•Intraepithelial P. gingivalis and F. alocis colonies are detected together in dysbiotic mucosa.•Increased metabolically active dual species can lead to higher microvasculature.•Invasion of intraepithelial microvessels leads to systemic pathogen dissemination.