Several impressive studies have made the case that the intestinal flora of cancer patients play a significant role in whether those patients respond to immunotherapy or not. The composition of a patient’s gut microbiota can significantly influence whether he or she responds to an immune checkpoint inhibitor, a type of cancer immunotherapy.
But what seemed to matter most wasn’t the level of a specific gut microbe, but rather the overall diversity of the person’s gut microbiome. It’s probably a community of bacteria. Patients who responded to the treatment, they actually had a much higher diversity of bacteria in their gut microbiomes compared to non-responders.
It also brings in the question of diet. Patients who have a fiber-rich diet with more whole grains—that is, with a more microbiome-friendly diet—might do better on cancer treatment. Such a diet help facilitate and enhance the immune system such that you might be able to ultimately prevent cancer.