Study Highlights New Data on Probiotics as Food Allergy Treatment for Children

A recent systematic review concluded that evidence was mixed on the efficacy of probiotics for pediatric food allergies, with findings showing limited benefits for reduction in eczema and potential tolerance acquisition with specific strains like Lactobacillus rhamnosus GG (LGG) over longer periods.1

This systematic review and meta-analysis was authored by a team of investigators led by Carol Stephanie C. Tan-Lim, from the department of clinical epidemiology at the University of the Philippines Manila College of Medicine. Tan-Lim and colleagues had, with their research, sought to update available data related to the safety and effectiveness of probiotics as a potential treatment for pediatric individuals with food allergy.

“In 2018, we published a systematic review and meta-analysis on the role of probiotics for treating food allergy in pediatric patients,” Tan-Lim and colleagues wrote. “Since 2018, several new studies relevant to this topic have been published. This systematic review aimed to update the available evidence on the effectiveness and safety of probiotics as treatment of food allergy.”1,2

Trial Design Details

The research team built their analysis on a series of randomized controlled trials (RCTs) that were featured in a prior 2018 systematic review in addition to RCTs published between February 2018 - March 2024. These RCTs had assessed probiotics’ efficacy in the management of food allergies among pediatric patients.

The screening, the extraction of data, and the analysis itself were all conducted by a set of 2 investigators. Their review considered studies written in all languages that involved individuals who were ≤18 years old with diagnoses of food allergies or suspected food allergies.

The ream classified diagnoses as confirmed if they were shown to be supported by standardized tests, such as double-blind placebo-controlled food challenges or food-specific IgE assessments. RCTs in the meta-analysis and review had focused on the oral administration of probiotics, irrespective of dosage, strain, or duration of treatment.

In the included analyses, each RCT’s control groups would have followed the standard care for food allergies. Trials in which probiotics had been paired with oral immunotherapy were all included in the systematic review only if the control cohort also had been treated with oral immunotherapy.

The investigators determined their primary outcome to be the alleviation of patients’ symptoms, which they evaluated by simply presence or absence of symptoms. They could also evaluate symptoms by using continuous variables, such as observed reductions in symptom severity scores. The research team noted that the SCORAD index was commonly implemented for the purposes of assessing severity of subjects’ symptoms.

In terms of secondary outcomes evaluated by the team, examples included the acquisition of tolerance, defined as systemic unresponsiveness to allergens. Other examples included the occurrence of adverse events, which the investigators assessed as binary outcomes.

Notable Findings

Overall, there were 13 RCTs included in this systematic review and a total of 1,608 pediatric patients who were noted as having allergies to food products. The findings resulting from a set of analyses indicated that probiotics likely had no significant impact on reductions of participants’ eczema scores for those reporting a cow’s milk allergy (mean difference [MD] −1.29 points, 95% CI −4.14 to 1.56; moderate certainty of evidence).

Despite this conclusion, the research team also identified evidence in a single RCT that suggested probiotics could potentially diminish childrens’ eczema scores among those who had various types of food allergies (MD −23.08 points, 95% CI −27.55 to −18.61; low certainty of evidence).

The team found that substantial benefits in tolerance induction were noted following 2 years at minimum of probiotic utilization (risk ratio [RR] 0.44, 95% CI 0.29 to 0.67; moderate certainty of evidence), indicating that probiotic administration’s use over time may impact health outcomes. Uncertainy remained, however, about the role of probiotics in tolerance induction among infants with cow’s milk allergy given the very low certainty of available evidence (RR 0.58, 95% CI 0.34 to 1.00).

After the investigators’ subgroup analyses, they concluded that probiotics containing the LGG strain were linked to substantial tolerance induction improvements among subjects (RR 0.41, 95% CI 0.28 to 0.62). Overall, the researchers concluded that probiotics had been well-tolerated by the evaluated participants, citing a lack of significant adverse events noted by investigators.

“The current evidence is insufficient to draw conclusions on the effectiveness of probiotics in treating food allergy,” they wrote. “Further well-designed RCTs focusing on specific food allergens and specific types of food allergy (IgE-mediated and delayed type of food hypersensitivity) are needed to draw clinically relevant conclusions.”1

References

1. Tan-Lim CSC, Esteban-Ipac NAR. Systematic review and meta-analysis on probiotics as treatment for food allergies among pediatric patients: A 2024 update. Pediatr Allergy Immunol. 2025 Jan;36(1):e70028. doi: 10.1111/pai.70028. PMID: 39803979.
2. Tan-Lim CSC, Esteban-Ipac NAR. Probiotics as treatment for food allergies among pediatric patients: a meta-analysis. World Allergy Organ J. 2018; 11(1): 25.