On the other hand, patients on a fiber-rich diet showed a five-fold increase in response. The study is present on April 2, 2019, at the American Association for Cancer Research (AACR) Annual Meeting 2019. The pioneering study was carried out by the Parker Institute for Cancer Immunotherapy (PICI) and The University of Texas MD Anderson Cancer Center. It explored the links between the diet of cancer patients, their gut microflora and their response to immunotherapy.

Probiotic supplements

The study showed that modifiable lifestyle factors could influence the gut microbiome and immunotherapy response in cancer patients. The study looked at 113 patients with metastatic melanoma who were starting immunotherapy at Houston’s MD Anderson. Around 42% of these patients were taking over-the-counter probiotic supplements. There was a 70% reduction in the odds that they would respond favorably to cancer immunotherapy with anti-PD-1 checkpoint inhibitors.

Poor diet is link to a worse response One possible explanation, according to the researchers; could be the reduce diversity of gut bacteria with probiotic supplementation. This is already known to affect the response to immunotherapy. The gut microbiome, which is composed of billions of intestinal bacteria; helps regulates the human immune system. Checkpoint inhibitors act via the immune defenses against cancer.

Potentiate cancer

Thus, influencing the composition of the gut flora could, in theory at least; be one way to potentiate cancer immunotherapy by stimulating immune function. Because In keeping with this hypothesis; therefore patients who ate a lot of whole grains (a good source of fiber, among other benefits) had a more diverse gut microbiome and better immunotherapy response.

Those who preferred processed meats and more sugar in their diets had fewer microflora species in their gut and showed a poorer response. The results are ‘surprising’ While the other observations are not unexpect; therefore the current study questions the general assumption that probiotics enhance gut health in cancer patients.

Probiotic supplements

Study author Christine Spencer call the findings “a bit surprising” and said more research would be need to follow up this conclusion. Jennifer Wargo confirmed this, saying, “Based on our early results, cancer patients and doctors should carefully consider the use of over-the-counter probiotic supplements, especially before beginning immunotherapy treatment.”
Eating a high-fiber diet has long been shows to have health benefits. In this case, we see signs that it is also link to a better response to cancer immunotherapy.” Anti-PD-1 checkpoint inhibitors are only successful in 20-30% of patients. Because Researchers are now searching for ways to enhance their effectiveness by regulating the diet and/or supplement intake. As Spencer points out, the study suggests an important relationship between diet, the gut microbiome, and response to immunotherapy, which needs to be further studied and exploited.