Immunotherapy uses a person’s own immune system to fight cancer. One such treatment uses immune checkpoint inhibitors—medicines that target proteins that switch immune cells on and off. Cohort and animal studies have suggested an individual’s gut microbiome may have an impact on their response to this treatment. A study published in the journal Science set out to determine if diet and supplement intake that might impact the microbial population in the gut affect immunotherapy response.
Researchers profiled the gut microbiome of patients being treated with immune checkpoint inhibitors for metastatic melanoma (skin cancer that has spread to other parts of the body) and surveyed their dietary habits and probiotic use.
Probiotic use was not associated with treatment outcomes. However, patients with higher dietary fiber intake—20 grams or more per day—lived longer without disease progression than those with lower dietary fiber intake. The authors calculated that every five-gram increase in daily fiber intake was associated with a 30 percent lower risk of progression to death.
These finding support the notion that your dietary habits may work in combination with traditional cancer therapies to improve treatment outcomes—which is an exciting area for more research.