Efficacy and Safety of Orally Administered Heat-Killed Lactobacillus Paracasei LCW23 in Patients with Allergic Rhinitis

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 × 10 9 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.