Evaluation of safety and human tolerance of the oral probiotic Streptococcus salivarius K12: A randomized, placebo-controlled, double-blind study

► We evaluate the safety of the novel oral cavity probiotic Streptococcus salivarius K12 in humans. ► Subjects took either probiotic or placebo for 28 days and were monitored for health impact. ► No statistically-significance differences were detected between the groups. ► Daily ingestion of large doses S. salivarius K12 does not adversely effect the human host.