Results from a recent small randomized clinical trial found that a combined probiotic and peanut oral immunotherapy (PPOIT) may potentially be an effective option to manage children with peanut allergy and the treatment effect may last for at least 4 years .
Previously, researchers at the Murdoch Children’s Research Institute (Melbourne, Australia) conducted a randomized, double-blind, placebo-controlled trial to investigate the effect of PPOIT in 62 children with peanut allergy. For 18 months, children received either placebo or PPOIT (2 x 1010 CFU of Lactobacillus rhamnosus CGMCC 1.3724┼┼ and 2 g of peanut protein per day) and were asked to avoid taking other probiotics and to remain on a peanut elimination diet. At the end of the study, 89.7% of children receiving PPOIT vs. 7.1% receiving placebo became desensitized to peanut (i.e., being able to tolerate peanut while on treatment). Two weeks after the study, 82.1% receiving PPOIT and 3.6% receiving placebo achieved sustained unresponsiveness (i.e. being able to tolerate peanut after stopping treatment) .
Four years after the trial had ended, the study investigators assessed outcomes in children from the original study, including 24 from the PPOIT group and 24 from the placebo group. The investigators found that 67% from the PPOIT group vs. 4% from the placebo group have continued eating peanut regularly. PPOIT-treated children had significantly smaller wheals in peanut skin prick test than children receiving placebo. In a subgroup of children who went on an 8-week peanut elimination diet followed by a double-blind food challenge (4 g peanut protein), 58% of children from the PPOIT group achieved sustained unresponsiveness vs. 7% from the placebo group.
Even though the results were encouraging, the investigators acknowledged there were a few limitations in this study. The study was conducted at a single center with a small sample size. The lack of a probiotic-only group in the trial limited the ability to understand how the individual constituents of PPOIT worked. The follow-up study was an observation study that no longer met the randomized trial setting; therefore, the observed effects cannot be solely attributed to the PPOIT intervention that took place four years ago. These limitations are being addressed via a larger, multicenter, randomized trial currently under way.
The study results published in The Lancet Child & Adolescent Health (August 2017).
┼┼The studied probiotic strain was also known as Lactobacillus rhamnosus NCC 4007 and was genetically indistinguishable from Lactobacillus rhamnosus ATCC 53103 (aka Lactobacillus rhamnosus GG, or LGG).
Some limitations to this preliminary study are:
- A single-center study design with a small sample size
- Lack of a probiotic-only group
- Lack of randomized trial setting in the follow-up observation period
Why is this Clinically Relevant?
- This is the first randomized controlled trial demonstrating peanut allergy may be manageable via oral immunotherapy that included a specific probiotic strain
- Although PPOIT appeared to be effective for peanut allergy, the same immunotherapy has not been tested for other types of food allergy (e.g., milk, egg)
- The most effective method to manage food allergy (including peanut allergy) is still allergen avoidance and education in the emergency management of allergic reactions. However, accidental exposure to food allergens remain very common, and the constant vigilance significantly impairs quality of life of those who are affected. PPOIT may be an option for families seeking additional approaches to manage peanut allergy
 Hsiao, K.-C., et al., 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 trial. The Lancet Child & Adolescent Health.
 Tang, M.L., et al., Administration of a probiotic with peanut oral immunotherapy: A randomized trial. J Allergy Clin Immunol, 2015. 135(3): p. 737-44 e8.