Ex vivo HNSCC clinical studies using saliva and antiviral or antibacterial chewing gums reveal reduction in carcinogenic microbes

Higher abundance of oral human papilloma virus (HPV), Porphyromonas gingivalis (Pg) and Fusobacterium nucleatum (Fn) correlate with worse survival of head and neck squamous cell carcinoma (HNSCC). One-third of males globally are HPV-positive, one-fifth have high-risk HPV-16 and is transmitted through oral sex. In our ex vivo clinical study of HNSCC patients, HPV ELISA detected viruses in 100% of saliva and 75% of oral-rinse samples (n = 44). Cell culture studies showed 1000-fold higher Pg/Fn in their saliva and 100-fold higher in oral-rinse samples than non-cancer control participants. Bean-lectin (FRIL) gum (trapped) aggregated 93% of HPV in saliva and 80% in oral-rinse samples in ELISA. Single dose of bean gum + protegrin-1 (antimicrobial peptide) reduced Pg/Fn > 99% in saliva and oral-rinse samples (n = 42). Although protegrin was effective against anaerobic Pg/Fn, it did not kill capsule forming bacteria including Streptococci, providing selectivity and protection of oral commensal bacteria. These findings from ex vivo clinical studies support potential value of advancing these biologics to clinical trials as adjuncts to current therapeutic strategies or as prophylaxis to control pathogenic microbes associated with HNSCC.