Streptococcus salivarius is a species of spherical, gram-positive, facultative anaerobic bacteria that is both catalase and oxidase negative. S. salivarius colonises (usually in chains) the mouth and upper respiratory tract of humans just a few hours after birth, making further exposure to the bacteria harmless in most circumstances.
Some strains of S. salivarius are marketed as a probiotic for oral health. Some strains of S. salivarius are found to produce BLIS (the above-mentioned bacteriocin-like inhibitory substances) which are peptides that display interspecies inhibition.
BLIS K12 and BLIS M18 are both specific strains of Streptococcus salivarius and the core of our oral probiotics.