The Red Cross is in desperate need of your poo - it takes guts, but it's for a good cause.

Perth is home to the only Lifeblood Microbiota Donor Centre in Australia - but many of their existing donors have been wiped out by COVID-19 and the cold and flu season.

Every donation is processed into life-saving faecal microbiota in transplant treatments for patients suffering infections like Clostridioides difficile.

Currently just a handful of microbiota donors remain, with 85 per cent of existing donors no longer able to give.

The Red Cross desperately needs 2400 Perth residents to sign up.

Perth A/Microbiome Manager Silvana Miney said to be eligible, donors must not have had COVID, must be aged between 18 and 50, and be able to regularly donate at the Microbiota Donor Centre in Perth CBD.

"FMT is made by collecting stool from a healthy donor, testing and processing it, then supplying it to hospitals to transplant to patients," Ms Miney said.

"It might seem like an unusual request, but there are more than a trillion life-saving microorganisms in your gut.

"Your healthy microbiota, something that normally gets flushed away, could be used to make FMT that can transform and even saves lives."

Ms Miney encouraged people to cast away the stigma and donate their poo.

"Just one in 100 people who enquire will be eligible to donate, so we need as many people as possible to sign-up," she said.