evidence: "Initially, we were astounded," says Iliyan Iliev, an immunologist at Weill Cornell Medicine in New York and one of the researchers who made the fungi-cancer connection. In addition to Candida, his team found several other fungal species that were associated with the disease, such as Blastomyces in lung cancer and Malassezia, a variety of yeast, tied to breast cancer. [...] Siew Ng, director of the Microbiota I-Center at the Chinese University of Hong Kong, says our body’s fungal community is a "small but crucial component" of the gastrointestinal microbiome in particular. But while gut fungi such as Candida, Saccharomyces, and Cladosporium are all fundamental to our health, they have also been linked to diseases. Candida, for instance, can overpopulate and cause dysbiosis, a disorder associated with many health issues, including colorectal cancer. In other words, good fungi can become too successful and run amok, and turn into bad fungi. [...] As for the connection between fungi and cancer cells, Iliev concedes that he initially considered it to be "biologically improbable," but he’s since shifted toward "cautious optimism" about unraveling more mysteries of the mycobiome. In another recent study, researchers at NYU, including Saxena, found that there are 20 distinct types of fungi that may someday be useful in distinguishing between people with cancer and those without, pushing forward the idea that early testing of fungi might pave the way for better diagnoses and treatment.