A team of Japanese researchers has started clinical trials to see if healthy intestinal bacteria improves the outcome of immunotherapy in certain cancer patients.

Immunotherapy, which boosts immunity in patients, is widely used for the treatment of stomach or esophageal cancer, but some patients do not respond well to it.

Researchers from the National Cancer Center Japan and Juntendo University are involved in the clinical trial.

Research overseas had shown that patients unresponsive to immunotherapy drugs have unbalanced intestinal bacteria.

Based on those overseas studies, the researchers will transplant bacteria from healthy people in patients before immunotherapy drugs are administered.

The researchers say that they intend to verify the safety and efficacy of the treatment method in clinical trials that involve up to 45 patients over the next three years.

They say that this is the first clinical trial in the country in which intestinal bacteria will be used to treat cancer in the digestive organs.

Shoji Hirokazu, chief physician at the National Cancer Center Hospital, is leading the initiative.

He said he hopes clinical trials will prove the method is safe and help the team better understand its mechanism.

He said he hopes the method will provide a new option in strategies to treat cancer.