Efficacy of Bifidobacterium longum and Lactobacillus plantarum (NVP-1703) in Children With Allergic Rhinitis: A Randomized Controlled Trial.

Background: There is increasing evidence that probiotics are effective in treating allergic rhinitis (AR), while some controversies remain. This study was performed to evaluate the therapeutic effect and safety of a mixture of Bifidobacterium longum and Lactobacillus plantarum (NVP-1703) in children with AR.

Methods: In a randomized, double-blind, placebo-controlled study, children aged 6 to 19 years with perennial AR were treated with NVP-1703 at a dose of 1 × 10¹⁰ CFU/day or placebo once a day for 4 weeks. Total nasal symptom score (TNSS), nasal symptom duration score (NSDS), quality of life (QoL), allergic inflammatory markers, and safety parameters were evaluated.

Results: After 4 weeks of treatment, the TNSS in the NVP-1703 group significantly decreased compared to that in the placebo group (P = 0.011), both in the morning and the evening (P = 0.031 and P = 0.004, respectively). The NSDS also significantly decreased in the NVP-1703 group compared to that in the placebo group (P = 0.018). QoL scores, particularly those related to mouth breathing and itchy nose, showed a significant improvement in the NVP-1703 group compared to the placebo group. The ratios of interleukin (IL)-4/IL-22 and IL-5/IL-22 were significantly reduced in the NVP-1703 group after the treatment compared to the baseline values. No notable adverse events were reported in the NVP-1703 group.

Conclusion: Oral administration of a mixture of B. longum and L. plantarum (NVP-1703) improved both AR symptoms and QoL in children with perennial AR, accompanied by decreases in the ratios of T helper 2 cytokines to IL-22.

Trial registration: Clinical Research Information Service Identifier: KCT0002661.