Patients with malignant melanoma are more likely to respond to immunotherapy treatment if they have greater diversity in the types of bacteria in their gut, according to new research presented at the National Cancer Research Institute’s (NCRI) Cancer Conference in Liverpool, U.K.
Scientists from the University of Texas MD Anderson Cancer Centre in Houston studied over 200 mouth and over 100 gut microbiome samples from people with advanced melanoma.
The researchers discovered that people whose cancer responded to immunotherapy treatment had more diversity in the types of bacteria found in their gut. They also found significant differences in the type of bacteria in the gut of people whose cancer responded versus those who didn’t.
Overall, there was no difference in the type of mouth bacteria between patients, the authors noted.
“Our research shows a really interesting link that may mean the immune system is aided by gut bacteria when responding to these drugs. Not all patients respond to immunotherapy drugs and it’s hard to know who will benefit from the treatment prior to it being given,” said Dr. Jennifer Wargo, lead researcher of the study, who was quoted in a press release.
“The gut microbiome can be changed through a number of different strategies, so there is real potential here to modify the gut microbiome to boost an immunotherapy response,” added Dr. Wargo, associate professor in the Department of Surgical Oncology, Division of Surgery at the University of Texas MD Anderson Cancer Center.
There is growing evidence that gut bacteria play a vital role in warding off disease, absorbing nutrients from food, and maintaining normal function of the immune system, said Dr. Pippa Corrie, chair of the NCRI’s Skin Cancer Clinical Studies Group.
“Gut microbes have been shown to influence the role of conventional chemotherapy, so it’s probably not surprising that they impact on response to new immunotherapies being used in the clinic. Manipulating the gut flora may be a new strategy to enhance the activity of immunotherapy drugs, as well as to manage problematic toxicity in the future.”