Gut bacteria that help immunotherapy fight melanoma

Defining mechanisms of how immune checkpoint inhibitor-associated bacteria modulate tumor immunity in cancer

NIH-funded research University of Pittsburgh at Pittsburgh · NIH-11310869

This project explores whether certain gut bacteria and their natural chemicals can help immunotherapy work better for people with melanoma.

Quick facts

Grant typeR01 grant
Study typeNIH-funded research
Funding institutionUniversity of Pittsburgh at Pittsburgh NIH-funded
Lab location1 site (Pittsburgh, United States)
Project IDNIH-11310869 on NIH RePORTER

What this research studies

From a patient perspective, researchers will follow bacterial species linked to better immunotherapy outcomes and study the small molecules those bacteria make. They will test how a bacterial metabolite called indole-3-aldehyde (I3A) changes immune killer (CD8) cells and boosts checkpoint drugs using lab-grown immune cells and mouse tumor models. The team will also analyze patient microbiome data and use molecular tools to pin down the pathways—like the aryl hydrocarbon receptor (AhR) and CREB—that mediate the effect. Together these steps aim to connect what is seen in patients with clear lab evidence of how the bacteria act.

Who could benefit from this research

Good fit: People with melanoma who are receiving or have received immune checkpoint inhibitor treatment, especially those who did not respond well, would be most relevant to this work.

Not a fit: Patients who do not have melanoma or are not treated with immune checkpoint drugs are unlikely to receive direct benefit from this project.

Why it matters

Potential benefit: If successful, this work could point to new probiotic or small-molecule approaches that make immune checkpoint therapies work better for melanoma patients.

How similar studies have performed: Previous patient-microbiome studies have linked certain gut bacteria to better immunotherapy outcomes, and the investigators have shown in preclinical models that L. reuteri–derived I3A can enhance anti-tumor immunity.

Where this research is happening

Pittsburgh, United States

Researchers

About this research

  1. This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
  2. Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
  3. For full project details, budget, and progress reports, visit the official NIH RePORTER page below.
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.