Study short name


Study full name

A multicentre, randomised, controlled trial evaluating the effectiveness of Probiotic and Peanut Oral Immunotherapy (PPOIT) in inducing desensitisation or tolerance in children with peanut allergy compared with Oral Immunotherapy (OIT) alone and with Placebo

Principle Investigator

Paxton Loke

Administering Institute

Murdoch Children’s Research Institute

Major funding source

National Health and Medical Research Council (NHMRC)

Study focus


Study design


Main study aim

To determine if Probiotic and Peanut Oral Immunotherapy (PPOIT) is more effective than placebo and/or peanut OIT alone in inducing sustained unresponsiveness (SU) in children with peanut allergy.

Additional study information

Peanut is the most common cause of life-threatening allergic reactions, and one of the commonest causes of death from food-induced anaphylaxis. There is currently no effective long-term treatment for food allergy.

We have previously shown that a novel treatment comprising a combination of a probiotic together with peanut allergen oral immunotherapy (PPOIT-001) is highly effective at inducing SU in children with peanut allergy, with benefit persisting to 4 years after treatment cessation in the majority of initial treatment responders. Eighty-two percent (82%) of PPOIT treated participants achieved SU to peanut as compared to only 3.6% of placebo-treated children.

Having demonstrated that PPOIT is highly effective in inducing SU in children with peanut allergy, it is now imperative to examine whether our combined PPOIT treatment is more effective than peanut OIT alone, i.e. whether the addition of probiotic to OIT results in added benefit.

PPOIT-003 is a multicentre, randomised, three-arm, double-blind placebo-controlled phase 2b trial, conducted in 3 children’s hospitals in Australia – the Royal Children’s Hospital Melbourne, Perth Children’s Hospital, and the Women’s and Children’s Hospital in Adelaide.

Study population

Participants (n=200) aged between 1 and 10 years of age, with current IgE-mediated peanut allergy as confirmed by failed double-blind placebo-controlled food challenge.

Study status

Recruitment completed March 2018. Data collection ongoing, through September 2020.

Australia New Zealand Clinical Trials Registry:

Main Publications: 

  1. Hsiao KC, Pitkin S, Axelrad C, Loke P, Tey D, Su EL, et al. Probiotic peanut oral immunotherapy (PPOIT) is effective at inducing 8-week sustained unresponsiveness after 18 months of treatmentAllergy. 2019;74:585-585. doi:
  2. Hsiao KC, Ponsonby AL, Axelrad C, Pitkin S, Tang MLK, Team PS. Long-term clinical and immunological effects of probiotic and peanut oral immunotherapy after treatment cessation: 4-year follow-up of a randomised, double-blind, placebo-controlled trialThe Lancet Child & Adolescent Health. 2017;1(2):97-105. doi: