Gut bacteria influence many aspects of our health, from our immune system to our brain. Increasingly, evidence shows these bacteria play a key role in how well cancer immunotherapy treatment works. They can either help the immune system fight cancer or interfere with its effects.
In a new forum article published in the journal Cell Metabolism, postdoctoral associate Rachel Newsome, Ph.D., and Christian Jobin, Ph.D., highlighted the potential for a paradigm shift in the field. Using a combination approach to both supplement the gut with healthy bacteria while also targeting harmful bacteria for removal could revolutionize responses to immunotherapy treatment, they said.
More than 15 ongoing clinical trials are studying whether supplementation with probiotics enhances patient responses to a type of immunotherapy treatment called immune checkpoint blockade. The trials are evaluating the potential benefit of probiotics — live bacteria and yeasts that have beneficial effects — in several types of cancer.
At the same time, clinical trials have shown that transplants with a healthy donor’s fecal microbiota introduce beneficial microbes and displace harmful ones in patients receiving immune checkpoint inhibitor therapy as their initial treatment for solid tumors.
Those findings mean the loss of harmful groups of bacteria may be as critical as adding beneficial ones to improve outcomes with immune checkpoint blockade, Newsome said.
“Although a lot of work is needed to understand which specific bacteria are lost and why this is beneficial to treatment response, there are numerous implications for this phenomenon, including potential new precision therapeutics that target and deplete specific bacteria,” Newsome said. “Ultimately, this new field of research could develop therapies to combine with the probiotic treatments currently being investigated in clinical trials to revolutionize cancer response to immunotherapy.”
“Ultimately, this new field of research could develop therapies to combine with the probiotic treatments currently being investigated in clinical trials to revolutionize cancer response to immunotherapy.”
Newsome and Jobin’s pioneering research has found that a small compound produced naturally by gut bacteria doubled the response to lung cancer immunotherapy treatment in mice. The team is working to make the compound into a drug for testing in humans.
Their work creating a pipeline to harvest the therapeutic potential of the microbiota represents a groundbreaking expansion of the field of microbiome science.
