Scientists find that skin cancer treatment depends on bacteria in the gut
Scientists have found out that depending on which bacteria inhabit a person's intestines, his immune system reacts differently to immunotherapy for skin cancer. This is a very important result, as one of the effective methods in the fight against melanoma is considered to be immunotherapy, when the human immune system is artificially "targeted" to the tumor. The results of the study are published in the journal Life Science Alliance.
But it does not help everyone. It has long been noticed that the effectiveness of the immune system in the fight against cancerous tumors depends on the composition of the intestinal microbiota. But why? The answer was sought by scientists from the Federal Research and Clinical Center for Physical and Chemical Medicine named after Academician Yuri Lopukhin FMBA, ITMO University and the Institute of Bioinformatics. They compared the microbial genomes of people who benefited from immunotherapy and those who did not. This allowed them to identify 84 bacteria in the presence of which immunotherapy brought recovery, and 53 bacteria when there was no treatment effect.
The analysis showed that the "good" microorganisms tend to be "altruistic" - they produce vitamins, amino acids and a full range of fatty acids that can be used by the human body and stimulate its immune system. The bacteria, on the other hand, which have been linked to unsuccessful immunotherapy, exhibit "selfish" behavior and, conversely, absorb important resources from the host's gut that come with food.
"The results obtained may be useful for predicting the efficacy of such treatments. Moreover, our findings allow us to predict the most suitable donor for microbiota transplantation, which will also improve the treatment," says project leader Evgeny Olekhnovich, Ph.D. candidate in biology.
In the future, the researchers intend to expand their analysis to include not only bacteria of the intestinal microbiota, but also its other components, such as fungi, protozoa, and bacteriophages - viruses that affect bacterial cells.