Gut bacteria do a lot. As Ed Yong writes at Not Exactly Rocket Science, they help in digesting food, fighting infections, and brain development. They also, he notes, appear to help some cancer therapies work, at least in mice.
Two independent groups of researchers — one at the US National Cancer Institute and the other in Gustave Roussy Institute in France — found that three cancer therapies seemed to rely on the gut microbiome to be effective.
In mice, the NCI team tested an immunotherapy and oxaliplatin, finding that both needed a bit of gut microbiome help to work — giving mice a dose of antibiotics with the cancer therapy lowered the therapy's effectiveness. The Gustave Roussy team found a similar effect with cyclophosphamide.
But just what this means for cancer patients isn't yet clear, Yong adds, not only as these findings need to be replicated in people, but also because clinicians may not want to take their patients off of antibiotics as cancer patients are susceptible to infections and if they wanted to instead treat them with a probiotic, which bacteria would be best to give isn't yet known.
"For me, the take-home message is that we cannot ignore the gut microbiome and the possibility that it has an impact on the response to cancer treatments," NCI's Romina Goldszmid tells Yong.