Posted on 11 February 2021
Longevity briefs provides a short summary of novel research in biology, medicine, or biotechnology that caught the attention of our researchers in Oxford, due to its potential to improve our health, wellbeing, and longevity.
Why is this research important: Melanoma is a serious skin cancer that spreads to other organs if not treated at an early stage. Immunotherapy is a form of cancer treatment that helps the body’s immune system to eliminate cancer cells. Unfortunately, over 40% of melanoma cases are not responsive to immunotherapy.
What did the researchers do: We know that populations of bacteria in the gut can affect the immune system, and previous studies suggest that faecal transplants can affect the response to immunotherapy. In this study, researchers took the bacteria-containing faecal matter from melanoma patients who responded well to immunotherapy, and transplanted it into patients who were unresponsive. They then gave them an immunotherapy treatment called pembrolizumab.
Key takeaway(s) from this research: Out of 15 patients who had never previously responded to immunotherapy, 6 experienced either a cessation of growth, a large reduction or a complete elimination of the cancer. These patients developed gut bacteria populations similar to those of the donors – in particular, their gut populations became richer in firmicutes and actinobacteria, two types of bacteria that have previously been linked to a good response to immunotherapy.
It is not clear why only six of the treated patients experienced benefits. Further studies will seek to confirm this effect in larger clinical trials. They will also aim to determine whether faecal transplants might be effective in other cancers, and to identify more precisely which kinds of bacteria are involved. It is hoped that a cocktail of the most beneficial microbes could then be delivered in the form of a pill, rather than as a faecal transplant, in order to improve immunotherapy outcomes.
Fecal microbiota transplant overcomes resistance to anti–PD-1 therapy in melanoma patients: https://science.sciencemag.org/content/371/6529/595