A small clinical trial of a new immunotherapy treatment has seen more than two-thirds of children with a peanut allergy cured.

Australian researchers have made a breakthrough in the treatment of deadly peanut allergies in children.

A small clinical trial conducted at the Murdoch Children's Research Institute resulted in two-thirds of the children being treated with an experimental immunotherapy treatment being rid of their allergy.

Importantly, their desensitisation to peanuts persisted for up to four years after treatment.

"These children had been eating peanut freely in their diet without having to follow any particular program of peanut intake in the years after treatment was completed," trial lead Mimi Tang said on Thursday.

Peanut allergy is the most common cause of anaphylaxis, a life-threatening allergic reaction, and one of the most common causes of food allergy deaths.

Immunologist and allergist Professor Tang has pioneered a new form of treatment that combines a probiotic with peanut oral immunotherapy, known as PPOIT.

Instead of avoiding the allergen, the treatment is designed to reprogram the immune system response to peanuts and over the longer term develop tolerance.

It's thought combining probiotics with the immunotherapy gives the immune system the "nudge" it needs, Prof Tang said.

A total of 48 children were enrolled in the PPOIT trial and were randomly given either a combination of the probiotic, Lactobacillus rhamnosus, together with peanut protein in increasing amounts, or a placebo, once daily for 18 months.

At the end of the first stage of the trial in 2013, 82 per cent of children who received the probiotic and peanut oral immunotherapy treatment were deemed tolerant to peanuts compared with just four per cent in the placebo group.

Four years later, the majority who gained initial tolerance were still eating peanut as part of their normal diet while 70 per cent passed a further challenge test to confirm long-term tolerance to peanut.

Prof Tang said the results were very exciting and had been life-changing for the children.

"We had children who came into the study allergic to peanuts, having to avoid peanuts in their diet, being very vigilant around that, carrying a lot of anxiety," she said.

"At the end of treatment, and even four years later, many of these children who had benefited from our probiotic peanut therapy could now live like a child who didn't have peanut allergy."

The results have been published in The Lancet Child & Adolescent Health.

If confirmed by larger clinical studies, the broader hope is that the treatment can impact more food allergies among children.

"This is a major step forward in identifying an effective treatment to address the food allergy problem in Western societies," Prof Tang said.