Harnessing the microbiome for the development of innovative strategies to increase immunotherapy efficacy in cancer patients: A study on a dietary fiber supplementation (PREImuno2)

Immunotherapy, in particular immune checkpoint inhibitors (ICI), represent one of the major advances in oncology in the past decade. However, many cancer patients do not respond to ICI. Recently, the microbiome has been identified as a potential underlying cause for resistance to ICI. Thus, researchers are currently investigating different possibilities to harness the microbiome for the development of innovative strategies to improve the response rate to ICI. Diet is a known microbiome regulator and might therefore play a significant role in therapy efficiency, potentially via the modulation of the immune system. However, dietary guidelines are poorly implemented in today’s cancer treatment plans. Here we will test a dietary fiber compound, ImunoBran®, with the aim to better understand how dietary fiber modulates the microbiome and consequently immune cells during cancer progression. We will perform a clinical randomized cross-over study in cancer patients undergoing ICI, as well as use humanized mouse cancer models to study the effect of fiber supplementation on therapy efficacy and on the host-microbiome cross-talk, which might further drive immune cell activation. The integration of the omics data from the patients and mouse models will specifically identify bacterial species and metabolites driving the beneficial effects of dietary fiber. Additionally, these results might lead to the identification of novel microbiome-based regulators (probiotics) alone or in combination with food supplements including ImunoBran®, for the benefit of cancer patients. Altogether this project will identify new intervention points targeting the host-microbiome crosstalk and contribute to the establishment of dietary guidelines for patients undergoing anti-cancer treatments. Finally, as the first study of its kind in Luxembourg, this project will help establish important collaborations between researchers and clinicians to develop innovative microbiome-based strategies for the improvement of cancer treatments in the future.