Systematic review and meta-analysis of probiotics in the treatment of allergic rhinitis

The purpose of this meta-analysis is to systematically evaluate the efficacy of probiotics on allergic rhinitis (AR).

Collecting randomized controlled trials (RCTs) with probiotics as intervention measures for AR, two researchers independently screened the literature, extracted the data and evaluated the methodological quality of the included studies, and used RevMan 5.3 software for meta-analysis to observe the effects of probiotics on Rhinitis Quality of Life (RQLQ) scores, Rhinitis Total Symptom Scores (RTSS), blood eosinophil count, total and antigen-specific serum immunoglobulin E (IgE) levels by using the fixed- or the random-effects model to calculate the pooled risk for significant heterogeneity.

A total of 2708 patients were included in 30 RCTs. Meta-analysis results showed that the RQLQ global scores (mean difference [MD] = -9.43; P < 0.00001), RQLQ nasal scores (MD = -1.52; P = 0.03), and RTSS nasal scores (MD = -1.96; P = 0.02) significantly improved in the probiotic group when compared with those in the placebo group. There was no significant difference in blood eosinophil count (MD = -0.09; P=0.82), RQLQ eye scores (MD = -1.45; P = 0.07), RTSS global scores (MD = -2.24; P = 0.26), RTSS eye scores (MD = -0.39; P = 0.31), total and antigen-specific serum IgE levels (MD = -0.04; P = 0.7 and MD = -0.08; P = 0.81) between the probiotic and the placebo group.

Compared with the placebo group, the quality of life and symptoms of patients with AR significantly improved in the probiotic group, thus providing a new potential method for the application of probiotics in AR. However, because of the limited evidence for the current study outcomes, the heterogeneity of research, and the differences in research results, more high-quality studies are needed to in the future.