Can a dose of healthy gut bacteria supercharge cancer immunotherapy?

NCT ID NCT03686202

First seen Jun 24, 2026 · Last updated Jun 27, 2026 · Updated 2 times

Summary

This study tests a treatment called MET-4, which is a defined mix of live bacteria from a healthy donor's stool, given to cancer patients alongside standard immunotherapy. The goal is to see if it is safe and can improve how well the immune system fights solid tumors. About 65 adults with advanced solid tumors will participate, and researchers will measure changes in gut bacteria and any side effects.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

Active substance

MET-4 (a defined mixture of live intestinal bacteria from a healthy donor)

What this could lead to

If it works, this could point toward a way to boost the effectiveness of immunotherapy in solid tumors by improving the gut microbiome.

What could go wrong

This is an early feasibility study with only 65 participants, so results may not apply broadly. Adding bacteria could also cause side effects like infections or digestive issues.

Disclaimer Read more

This is a summary of the original study . Summaries may miss details or leave out important information. Before applying or accepting participation, make sure you have read and understood the full study. Curemydisease.com takes no responsibility whatsoever for anything missed, misunderstood, or acted upon as a result of our summary — we know it does not capture everything.

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Conditions

The condition(s) this trial relates to.

metastatic neoplasm

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

Contacts and locations

Locations

  • Princess Margaret Cancer Centre

    Toronto, Ontario, M5G 2M9, Canada