The role of probiotics for people being treated for cancer was a hot topic at the recent Society for Integrative Oncology conference. These supplements contain microbes that help colonize the gut ecosystem known as the microbiome. But they may reduce microbiome diversity.

That diversity is a key predictor of checkpoint inhibitor immunotherapy success, explained Jennifer McQuade, MD, of MD Anderson Cancer Center in Houston.  As previously reported in Cancer Health, patients who take probiotics are less likely to respond to immunotherapy.

To promote microbiome diversity, Johanna W. Lampe, PhD, of the Fred Hutchinson Cancer Research Center in Seattle, suggests eating a varied high-fiber diet that includes whole grains, vegetables (including cruciferous vegetables, carrots and onions), fruit (including berries), healthy fats from nuts and seeds, some fermented foods (such as yogurt) and minimal red meat and processed foods. “For most people, feeding your own microbes with these foods is a better idea than probiotic supplements,” she said. 

However, if you are not a candidate for immunotherapy, under certain circumstances taking probiotics on a short-term basis before treatment may reduce side effects. Charlotte Gyllenhaal, PhD, of the Block Center for Integrative Cancer Treatment in Skokie, Illinois, reports that studies show probiotics substantially reduced infection rates after colon cancer surgery and diarrhea after radiation treatment for cervical cancer.