Fecal transplants could help patients on cancer immunotherapy drugs

Source: Science Magazine, May 2019

ATLANTA—Oncologists deploy an array of strategies to stop cancer, from chemotherapy to radiation to drugs that boost the body’s immune defenses. Now, another potential therapy is being tested in clinical studies: fecal transplants. Early results from two groups described at the annual meeting of the American Association for Cancer Research (AACR) here this week suggest some patients who initially did not benefit from immunotherapy drugs saw their tumors stop growing or even shrink after receiving a stool sample from patients for whom the drugs worked. However, researchers caution, the results are preliminary.

During a fecal transplant, a stool sample from a healthy donor is moved into the gut of a sick person. The idea is that gut microbes from the healthy person will populate the sick person’s gut and improve their health. Fecal transplants are already in use as a treatment for stubborn colon infections of the bacterium Clostridium difficile. But until now, fecal transplants haven’t been tested as part of cancer therapy.

Although the two studies have so far followed only a handful of patients for a few months, researchers say their initial results are exciting. “This is the first clinical evidence that you may have an impact on antitumor immunity and potentially even responses,” says melanoma researcher Jennifer Wargo of MD Anderson Cancer Center in Houston, Texas, who is leading a similar clinical trial just getting underway.