New research is revealing that cancer is rife with bacteria and fungi — a rich ecosystem that scientists call the tumor microbiome.
Look up an image of a tumor on Google, and you’ll probably end up with a brightly colored cluster of cancer cells on a drab background of healthy tissue. But for Lian Narunsky Haziza, a cancer biologist at the Weizmann Institute of Science in Israel, the picture looks very different. A tumor may also contain millions of microbes, representing dozens of species.
Scientists have long known that our bodies are home to microbes, but have tended to treat tumors as if they were sterile. In recent years, however, researchers have laid that notion to rest, demonstrating that tumors are rife with microbes.
In 2020, several research teams showed that tumors are home to various blends of bacteria. And on Thursday, two studies published in the journal Cell found that tumors are also home to many species of fungi.
This so-called tumor microbiome is proving so distinctive in each type of cancer that some scientists hope to find early signs of hidden tumors by measuring the microbial DNA they shed into the blood. And some research hints that microbes may make tumors more aggressive or resistant to treatments. If that proves to be the case, it may be possible to fight cancer by attacking a tumor’s microbiome along with the tumor itself.