Healthy gut microbiomes are being used in an Australian-first "poo transplant" trial aimed at saving the lives of severely ill blood cancer patients.

A faecal microbiota transplant (FMT) involves extracting trillions of gut microbes from a healthy person's stool and transferring them to a patient lacking a robust gut biota to help improve their immune responses.

Ten blood cancer patients will be part of a trial being conducted by the QIMR Berghofer Medical Research Institute in Brisbane over the next year and funded by the Royal Brisbane and Women's Hospital.

It's the first time FMT has been tried on Australian patients living with severe graft-versus-host-disease (GVHD), which is caused when a donor's immune cells attack a recipient's organs and tissues after a bone marrow transplant.

QIMR Berghofer scientist Dr Andrea Henden will lead the study, which will use an FMT product developed by Australian Red Cross Lifeblood at the Royal Brisbane hospital.

Dr Henden hopes the trial will reveal whether gut microbes hold the key to a positive immune response to GVHD, and to treating the disease.

"A bone marrow transplant can be a double-edged sword. It saves the lives of people with aggressive blood cancers but can then take their lives by causing GVHD which is heartbreaking," she said in a statement.

GVHD patients are often hospitalised for long periods of time and are dependent on immune-suppressing medications, which fail to work in half of cases.

If doctors can restore a healthy gut microbiome in patients, they can potentially treat GVHD in a safer way that preserves the person's immunity, Dr Henden said.

"FMT is a really exciting new approach that could save lives."

Stools are collected from volunteer donors after rigorous screening before they are processed and tested at a TGA-licensed facility and then shipped to health and research facilities.

The treatment has shown to be 90 per cent effective in treating another gut infection, and Red Cross Lifeblood executive director Stuart Chesneau said his organisation is thrilled to be part of the new research.

"Emerging science shows that the microbiome has a far greater effect on health than anyone previously imagined," he said.