Combined probiotic and peanut oral immunotherapy for the treatment of peanut allergy: A randomised trial

RATIONALE: Co‐administration of a bacterial adjuvant with oral immunotherapy (OIT) has been suggested as a potential treatment for food allergy but such combined therapy has not previously been evaluated by randomized controlled trial. METHODS: A double‐blind placebo‐controlled randomized trial of probiotic Lactobacillus rhamnosus CGMCC 1.3724 and peanut OIT (PPOIT) in children (1‐10 years) with peanut allergy. Primary outcome was induction of sustained unresponsiveness (2‐5 weeks after discontinuation of treatment). Secondary outcomes were desensitization, and peanut skin prick test, sIgE and sIgG4. RESULTS: Sixty‐two children were randomized, stratified by age (<5yr, >5yr) and peanut skin test wheal size (<10mm, >10mm); 56 reached trial end. Baseline demographics were similar across groups. Two‐week sustained unresponsiveness was achieved in 82.1% receiving PPOIT and 3.6% receiving placebo (p<0.001). Nine children need to be treated for seven to achieve two‐week sustained unresponsiveness (NNT 1.27; 95% CI 1.06, 1.59). 89.7% receiving PPOIT and 7.1% receiving placebo were desensitized (p<0.001). PPOIT was associated with reduced peanut SPT and sIgE, and increased peanut sIgG4 (all p<0.001). PPOIT participants reported a greater number of adverse events, mostly with maintenance phase home dosing. CONCLUSIONS: This is the first randomized placebo‐controlled trial evaluating the novel co‐administration of probiotic and peanut OIT and assessing for sustained unresponsiveness in children with peanut allergy. PPOIT was effective in inducing two‐week sustained unresponsiveness, and immune changes that likely reflect reprogramming of the peanutspecific immune response. Further work is required to confirm sustained unresponsiveness after a longer period of secondary peanut elimination and to clarify the relative contributions of probiotic vs OIT.