Skip to main content


Previously, we showed that the growth, antibiotic resistance, and biofilm formation properties of the pathogens Pseudomonas aeruginosa and Klebsiella pneumonia were tremendously inhibited by the cell-free supernatant of the oral probiotic Streptococcus salivarius M18. These anti-pathogenic activities of the supernatant were more efficient under acidic conditions. The present approach takes advantage of the acidic nature of the tumor microenvironment to evaluate the effect of the S. salivarius M18 postbiotics on colon cancer cells. In both two-dimensional (2D) and three-dimensional (3D) cell culture models, S. salivarius M18 cell-free supernatant showed anti-cancer actions in the pH conditions mimicking the acidity of the tumor. The inhibitory effect was more prominent when the colon cancer cells have been treated with the cell-free supernatant obtained from the inulin incubated S. salivarius M18. The results of this study point out the potential of the S. salivarius M18 functional probiotic products to be used for targeting low pH environments including the unique acidic microenvironment of tumors.

Keywords: Cancer targeting; Colon cancer; Inulin; S. salivarius M18; Tumor microenvironment; pH.

Research Insights

SupplementHealth OutcomeEffect TypeEffect Size
Streptococcus salivarius M18Enhanced Natural Killer Cell Tumoricidal ActivityBeneficial
Streptococcus salivarius M18Reduced Colon Cancer Cell GrowthBeneficial

Pillser helps you make informed health decisions by providing comprehensive, unbiased information about supplements. This includes detailed research on supplement ingredients, their benefits, potential risks, and their overall efficacy. You can contribute by sharing your feedback and suggestions.

Send us an email at