Gut Bacteria Transplants Double Kidney Cancer Survival Time

For people battling kidney cancer, a surprising treatment is showing real promise: transplanting gut bacteria from cancer survivors into their digestive systems.

In a groundbreaking trial, 45 adults with kidney cancer received either stool transplants from a cancer survivor or a placebo while taking standard immunotherapy drugs. The results were striking.

Patients who received the transplants kept their cancer stable for two years on average. Those who got the placebo only maintained stability for nine months.

Even better, more than half of the transplant group saw their tumors actually shrink. Only about one third of the placebo group experienced the same benefit.

The treatment works by changing the mix of bacteria living in the gut, which directly affects how well the immune system fights cancer. Scientists believe certain bacteria help create immune cells that attack tumors more effectively.

The procedure itself is straightforward and already approved for treating stubborn bacterial infections. Doctors transfer stool samples from a healthy donor into the patient's gut through a small tube, followed by oral pills in later doses.

Analysis revealed the transplants introduced helpful bacteria like Blautia wexlerae, which produces compounds that boost anti-cancer immune cells. The transplants also reduced harmful inflammation-causing bacteria while increasing strains that support a healthier gut environment.

A separate trial released the same week showed similar success using stool transplants for lung cancer patients. Together, these studies suggest the approach could work for multiple cancer types that respond to immunotherapy, including bladder and head and neck cancers.

The Ripple Effect

This research opens doors for millions of cancer patients worldwide who don't respond well to current immunotherapy treatments. If larger trials confirm these results, doctors could offer a safe, relatively simple procedure that makes existing cancer drugs work better.

Scientists are now working to identify exactly which bacteria strains provide the most benefit. That knowledge could lead to creating artificial bacterial mixtures that can be mass produced, making the treatment accessible to far more patients without requiring individual donors.

The approach represents a fundamental shift in cancer treatment: instead of just attacking tumors directly, doctors can now enlist trillions of microscopic allies already living inside us.