Phage-based biocontrol of <i>Porphyromonas gingivalis</i> through indirect targeting

Lytic phages are valuable agents for targeted elimination of bacteria in diverse applications. Nevertheless, lytic phages are difficult to isolate for some target pathogens. We offer proof of concept that this limitation may be overcome via indirect phage targeting, which involves knocking out species that interact closely with and benefit the primary problematic target bacteria. Our target (<i>P. gingivalis</i>) only forms a periodontal pathogenic biofilm if the pioneer colonizer (<i>S. gordonii</i>) offers its surface for <i>P. gingivalis</i> to attach. Phage predation of the co-adhesive <i>S. gordonii</i> significantly reduced abundance of the target pathogen by >99%, decreased the total biofilm biomass by >44%, and suppressed its production of cytotoxic metabolic byproducts. Thus, this research extends the scope of phage-based biocontrol for public health protection.