Researchers at the University of California San Diego discovered that some strains of Staphylococcus epidermidis, a bacterium that lives harmlessly on human skin, produce a molecule called 6-HAP that selectively blocked the growth of tumor cell lines in the lab.
Injecting 6-HAP into mice slowed the growth of melanoma tumors without visible toxicity to the animals. Mice colonized with a 6-HAP-producing strain of S. epidermidis developed fewer ultraviolet-induced skin tumors than mice colonized with a strain that did not make the molecule, pointing to the bacterium's 6-HAP as the difference.
Searching human skin samples, the team found 6-HAP-producing S. epidermidis strains in multiple healthy people, suggesting some individuals may already carry a degree of this bacterial protection without knowing it. The anti-tumor effect was demonstrated in mice, not people, and a 2019 technical comment by other researchers disputed the 6-HAP results, which the authors rebutted.
Read the original study
Nakatsuji et al., Science Advances, 2018 · doi.org/10.1126/sciadv.aao4502
A bacterium on the skin may help guard it.
Source
- Nakatsuji, T., Chen, T. H., Butcher, A. M., Trzoss, L. L., Nam, S.-J., Shirakawa, K. T., Zhou, W., Oh, J., Otto, M., Fenical, W., & Gallo, R. L. (2018). A commensal strain of Staphylococcus epidermidis protects against skin neoplasia. Science Advances, 4(2), eaao4502. https://doi.org/10.1126/sciadv.aao4502