“Abundant numbers of several species of Candida, Saccharomyces cerevisiae and Cyberlindnera jadinii have been found in gastrointestinal tumours, while Blastomyces and Malassezia species are abundant in lung and breast tumours, respectively.”

AND

“Overall, these results suggest an involvement of fungi, especially Candida, in the pathogenesis of gastrointestinal cancers but also highlight their potential as a therapeutic target and prognostic tool.”

Sources:

1. Dohlman AB, Klug J, Mesko M, et al. A pan-cancer mycobiome analysis reveals fungal involvement in gastrointestinal and lung tumors. Cell 2022 ; 185 : 3807-22.e12.
2. Sepich-Poore GD, Zitvogel L, Straussman R, et al. The microbiome and human cancer. Science 2021 ; 371 : eabc4552.
3. Nejman D, Livyatan I, Fuks G, et al. The human tumor microbiome is composed of tumor type-specific intracellular bacteria. Science 2020 ; 368 : 973-80.
4. Alam A, Levanduski E, Denz P, et al. Fungal mycobiome drives IL-33 secretion and type 2 immunity in pancreatic cancer. Cancer Cell 2022 ; 40 : 153-67.e11.

This made me wonder whether the probiotic, Saccharomyces boulardii, might be a cancer risk given it’s very similar to Saccharomyces cerevisiae. I don’t think this study suggests that but this is very much not my field!