Evaluation of Safety and Human Tolerance of Oral Probiotic Streptococcus Salivarius eK12

The human oral cavity contains a diverse community of microorganisms essential for oral and overall health. Streptococcus salivarius K12 (eK12) has emerged as a promising oral probiotic due to its natural colonization of the throat and its ability to inhibit pathogens such as Streptococcus pyogenes, a major cause of streptococcal pharyngitis. It supports oral hygiene by producing antimicrobial substances like salivaricins and inhibiting odor-causing bacteria. The engineered eK12 variant (Bactoblis® Evol) has been developed to overcome inactivation by GAS-secreted protease SpeB, thereby enhancing its prophylactic potential against Group A Streptococcus (GAS) colonization. This clinical study includes a randomized, double-blind, placebo-controlled trial in Pakistan to evaluate the safety and human tolerance of eK12 in healthy adults. To enhance generalizability, an additional open-label cohort of healthy adults in Italy will receive eK12 without a control group.