Giving Cancer Cells a Taste of Their Own Medicine: Lactic Acid from Vaginal Microbiota Protects Against Cancer

Abstract

Cancer is a leading cause of morbidity and mortality worldwide, with cervical cancer ranking among the top four most common malignant tumors in females. Tumor microenvironments surrounding solid tumors, including cervical cancer, have often been found to contain high concentrations of lactic acid due to a preference for aerobic glycolysis, termed the Warburg effect. Several studies have implicated lactic acid in solid tumors’ ability to evade immune defenses, but lactic acid’s role in the human body is far from being one-sided. Lactobacillus species, the most common bacteria in the vaginal tract, have long been known to play a protective role in the vaginal microbiota by secreting lactic acid that inhibits the growth of pathogens. Recent research by Fan et al. uncovered that the beneficial effects of lactic acid produced by Lactobacillus species not only prevent vaginal infections but also protect against cervical cancer by regulating the fucosylation of vaginal epithelial cells. Hence, vaginal Lactobacillus gives cervical cancer cells a taste of their own medicine: using high doses of the very molecule that cancer cells may use to evade the immune system to suppress the cancer cells’ growth.