Efficacy and safety of orally administered heat-killed Lactobacillus paracasei LCW23 in patients with allergic rhinitis: A randomized controlled clinical trial

Objective: In this study, we primarily evaluated the effects of IMMUPHYLA LCW23 on symptoms of allergic rhinitis. IMMUPHYLA LCW23 is a commercial probiotic product containing the Lactobacillus paracasei LCW23 strain. Materials and Methods: Sixty 5–18-year-old children with allergic rhinitis positive for the dust mite-specific bivalent antibody and meeting the inclusion criteria were enrolled in this double-blind, randomized, placebo-controlled trial. They were administered 2–4 g of the probiotic product containing L. paracasei LCW23 (2.5 × 109 cells/g; n = 28) or a placebo supplement (n = 32) according to their body weights for 12 weeks. After the treatment period, a self-assessment of allergic rhinitis symptoms in the nose and eyes was performed. Results: This study results revealed that 12-week supplementation with IMMUPHYLA LCW23 is safe, with no side effects. In addition, the Pediatric Rhinoconjunctivitis Quality of Life Questionnaire (PRQLQ) assessment revealed that the probiotic significantly alleviated general discomfort (P = 0.003) and common symptoms of allergic rhinitis, such as nasal congestion (P = 0.033), runny nose (P = 0.001), and blowing nose (P = 0.008). Conclusion: Administration of IMMUPHYLA LCW23 was safe in the long-term follow-up study. The probiotic likely reduced the risk of allergy prevalence, without any major side effects.