Effectiveness and safety of probiotic therapy for pediatric allergic rhinitis management: A systematic review and meta-analysis

This meta-analysis aimed to evaluate the effectiveness and safety of probiotics for allergic rhinitis (AR) management in children. In total, 6 databases were searched, and 26 randomized controlled trials that compared the effects of probiotics with those not using probiotics in pediatric AR were included. Methodological quality was assessed using the Cochrane risk-of-bias tool. Data for relevant endpoints were extracted and analyzed. Our meta-analysis of the effectiveness of probiotics for pediatric AR showed that probiotics improved the remission rate of nasal symptoms (risk ratio (RR) 1.21, 95% confidence interval (CI) 1.04 to 1.40; P = 0.01), reduced the Total Nasal Symptoms Scores (TNSS) (weighted mean difference (WMD) −2.58, 95% CI -2.77 to −2.39; P < 0.00001) and the total scores of Pediatric Rhinoconjunctivitis Quality of Life Questionnaire (PRQLQ) (for frequency of symptoms: WMD -9.51, 95% CI -10.34 to −8.69; P < 0.00001; and for level of bother: WMD -9.27, 95% CI -10.13 to −8.41; P < 0.00001). Furthermore, they reduced the serum levels of interleukin-4 (IL-4) (WMD -13.86 ng/L, 95% CI -15.92 to −11.81; P < 0.00001), IL-6 (WMD -13.70 pg/mL, 95% CI -16.34 to −11.07; P < 0.00001), and IL-17(WMD -5.41 pg/mL, 95% CI -7.29 to −3.52; P < 0.00001), and significantly elevated the serum levels of interferon-γ (WMD 9.08 ng/L, 95% CI 8.10 to 10.06; P < 0.00001) and IL-10 (WMD 7.82 pg/mL, 95% CI 5.01 to 10.63; P < 0.00001). Probiotics also reduced the duration of cetirizine use in pediatric AR (WMD -2.88 days, 95% CI -4.50 to −1.26; P < 0.0005). No obvious adverse reactions were found to be related to probiotic treatment. This meta-analysis indicated that probiotic therapy can partially improve pediatric AR outcomes, assisted by modulating immune balance and reducing anti-allergic medication use, without obvious adverse reactions.