The human gut microbiome is fascinating and researchers are constantly finding new links between the microbes that inhabit our digestive tract and various aspects of our health.
Recently, scientists were looking at why some cancer patients respond well to immunotherapy drugs while others do not. They made an interesting discovery.
Immunotherapy drugs are an important weapon in the fight against cancer, but they don’t work for everybody. In fact, these drugs only only work in about 40% of patients with melanoma.
Researchers at the University of Pittsburgh suspected the microbiomes of patients might play a role, so they collected stool samples from patients who responded well to the immunotherapy treatment and transplanted the faeces – and the microbes – into the guts of patients who had not responded to the drugs.
Six of the 15 patients involved in the trial responded to immunotherapy for the first time, with either tumour reduction or disease stabilisation lasting more than a year. In these patients, the response to the transplant was a buildup of antibodies that scientist suspect and help prime the immune system to hunt down cancer cells. These patients also showed higher levels of activated T-cells, immune cells that target and kill cancer cells.
As the other 9 patients involved did not benefit from the fecal transplant, researchers suspect the gut microbiome may be one of many factors at play. Some had dissimilar gut microbiomes to the donors, suggesting that the introduced bacteria could not thrive in their new environment.
Further research is needed into this encouraging new development.