Administration of a probiotic with peanut oral immunotherapy: A randomized trial

Coadministration of a bacterial adjuvant with oral immunotherapy (OIT) has been suggested as a potential treatment for food allergy.

To evaluate a combined therapy comprising a probiotic together with peanut OIT.

We performed a double-blind, placebo-controlled randomized trial of the probiotic Lactobacillus rhamnosus CGMCC 1.3724 and peanut OIT (probiotic and peanut oral immunotherapy [PPOIT]) in children (1-10 years) with peanut allergy. The primary outcome was induction of sustained unresponsiveness 2 to 5 weeks after discontinuation of treatment (referred to as possible sustained unresponsiveness). Secondary outcomes were desensitization, peanut skin prick test, and specific IgE and specific IgG4 measurements.

Sixty-two children were randomized and stratified by age (≤5 and >5 years) and peanut skin test wheal size (≤10 and >10 mm); 56 reached the trial's end. Baseline demographics were similar across groups. Possible sustained unresponsiveness was achieved in 82.1% receiving PPOIT and 3.6% receiving placebo (P < .001). Nine children need to be treated for 7 to achieve sustained unresponsiveness (number needed to treat, 1.27; 95% CI, 1.06-1.59). Of the subjects, 89.7% receiving PPOIT and 7.1% receiving placebo were desensitized (P < .001). PPOIT was associated with reduced peanut skin prick test responses and peanut-specific IgE levels and increased peanut-specific IgG4 levels (all P < .001). PPOIT-treated participants reported a greater number of adverse events, mostly with maintenance home dosing.

This is the first randomized placebo-controlled trial evaluating the novel coadministration of a probiotic and peanut OIT and assessing sustained unresponsiveness in children with peanut allergy. PPOIT was effective in inducing possible sustained unresponsiveness and immune changes that suggest modulation of the peanut-specific 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 probiotics versus OIT.