The key finding is that patients with malignant melanoma (where the disease has spread) respond to immunotherapy treatment more effectively if they have a wider diversity in their gut bacteria compared with patients who have a narrower range of different gut microbes. The finding adds further to the body of work showing the importance of an individual’s microbiome.
This comes from work conducted by the University of Texas MD Anderson Cancer Center. Scientists examined some 200 mouth and 100 gut microbiome samples from patients diagnosed with advanced melanoma. The analysis showed that some patients responded to immunotherapy treatment better than others, and these patients had a wider diversity of gut bacteria. The oral bacterial differences had no impact.
The implications of the research are that varying the population and range of bacteria in the gut may help the effectiveness of immunotherapy, although further study would be needed to substantiate this claim. Gut bacteria can vary and diversity decreases when antibiotics are administered and diversity can increase when probiotics are taken.
Immunotherapy is a medical process where the body’s own immune system is harnessed to fight infections, such as cancer cells. One observation with such a treatment is that people respond in different ways and researchers are keen to understand why this is the case. Melanoma is a type of skin cancer that can spread to other organs in the body.
The results have yet to be published in a journal, however the findings were recently presented to the National Cancer Research Institute’s (NCRI) Cancer Conference in Liverpool, U.K. Here one of the researchers, Dr Jennifer Wargo, explained: “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.”
The next steps with the research will investigate how the gut microbiome might be changed and whether this has a beneficial effect in terms of immunotherapy treatment.
