Research Update: Clinician-Scientist Award supports breakthrough insights into how the microbiome shapes immunotherapy response in lung cancer

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer and remains one of the leading causes of cancer-related death in Canada. While immunotherapy has transformed outcomes for some patients by harnessing the body’s immune system to fight cancer, many still do not respond—and until recently, it has been difficult to predict who will benefit. Emerging research suggests that the microbiome—the trillions of bacteria living in and on our bodies—may play a critical role in shaping these responses.

In 2022, Dr. Bertrand Routy received a Marathon of Hope Cancer Centres Network (MOHCCN) Clinician-Scientist Award to explore how bacteria in the gut, blood, and tumours influence the immune environment in NSCLC and impact response to immunotherapy. This funding enabled his team to generate new insights into the relationship between microbiomes and cancer progression, including the identification of specific bacteria associated with tumour growth. It also supported the development of microbiome-based biomarkers and helped catalyze national collaborations to accelerate validation and clinical translation.

Now that his project has concluded, we caught up with Dr. Routy to learn more about the impact of this funding, how these findings are advancing precision oncology, and what they could mean for patients with lung cancer.

MOHCCN: How would you describe the original objectives of your project to a lay audience?

Dr. Routy: The goal of this research project was to understand how bacteria living in the gut, blood, and tumours influence the response of lung cancer patients to immunotherapy, a cancer treatment that helps the body’s own immune system recognize and attack cancer cells, and predict who will benefit from treatment.

What were you able to achieve through this project? How did funding from the Marathon of Hope Cancer Centres Network help you achieve these goals?

Through this project, we gained early insight into how changes in bacteria in the gut, blood, and lung may influence cancer development and how patients respond to immunotherapy. We identified a lung bacterium, Prevotella melaninogenica, that is increased in the lung of cancer patients. In preclinical models, this bacteria appears to promote cancer growth. Funding from the Network supported the main research activities needed to generate these findings and helped move the project toward the next stage of validation.

How are these findings helping to advance precision medicine for cancer? What potential impact could they have on patients?

By mapping the bacteria found in the gut, blood, and tumours, doctors can predict treatment success in advance, allowing them to choose the treatment most likely to work for each individual. The findings may also suggest ways of favourably modifying a patient’s microbiome (our body’s bacteria ecosystem) through innovative ways like diet, probiotics, or other approaches to boost their immune response.

How has funding from the Network helped advance your career as a clinician-scientist? Has becoming part of the Network helped open new opportunities?

Through the Network, I established collaborations with participating Canadian centers that accelerated validation of our microbiome‑based biomarkers. Moreover, these partnerships enabled our team to launch several microbiome trials in oncology (Routy et al, Nat Med 2023; Duttagupta et al, Nat Med 2026) and positioned the CHUM Microbiome Centre for broader clinical implementation and patient impact.

Published papers

• Duttagupta, S., Messaoudene, M., Hunter, S. et al. Fecal microbiota transplantation plus immunotherapy in non-small cell lung cancer and melanoma: the phase 2 FMT-LUMINate trial. Nat Med (2026). https://doi.org/10.1038/s41591-025-04186-5
• Routy, B., Lenehan, J.G., Miller, W.H. et al. Fecal microbiota transplantation plus anti-PD-1 immunotherapy in advanced melanoma: a phase I trial. Nat Med 29, 2121–2132 (2023). https://doi.org/10.1038/s41591-023-02453-x
• Diop, K., Pidgeon, R., Diop, A. et al. Characterization and description of Gabonibacter chumensis sp. nov., isolated from feces of a patient with non-small cell lung cancer treated with immunotherapy. Arch Microbiol 205, 338 (2023). https://doi.org/10.1007/s00203-023-03671-0