Exploiting the Acidic Extracellular pH: Evaluation of Streptococcus salivarius M18 Postbiotics to Target Cancer Cells

Area of Science:

• Microbiology
• Cancer Research
• Probiotics

Background:

• Streptococcus salivarius M18's cell-free supernatant inhibits Pseudomonas aeruginosa and Klebsiella pneumonia.
• This inhibition is more effective under acidic conditions.
• The tumor microenvironment is characteristically acidic.

Purpose of the Study:

• To evaluate the anti-cancer effects of S. salivarius M18 postbiotics on colon cancer cells.
• To leverage the acidic tumor microenvironment for targeted cancer therapy.

Main Methods:

• Utilized two-dimensional (2D) and three-dimensional (3D) colon cancer cell culture models.
• Treated cancer cells with S. salivarius M18 cell-free supernatant under acidic pH conditions.
• Compared efficacy of supernatant from inulin-incubated S. salivarius M18.

Main Results:

• S. salivarius M18 cell-free supernatant demonstrated anti-cancer activity in acidic conditions mimicking tumors.
• The inhibitory effect on colon cancer cells was enhanced by using supernatant from inulin-incubated S. salivarius M18.
• The study confirmed anti-cancer actions in both 2D and 3D cell culture models.

Conclusions:

• S. salivarius M18 postbiotics show potential as a therapeutic strategy for colon cancer.
• The acidic tumor microenvironment can be exploited for targeted delivery and efficacy of these postbiotics.
• Functional probiotic products derived from S. salivarius M18 could be developed for targeting acidic tumor environments.