Prevention and alleviation of allergic rhinitis by oral administration of Lacticaseibacillus paracasei GOLDGUT-Lpc969

Introduction Allergic rhinitis (AR) is a widespread upper airway disorder characterized by inflammation of the nasal passages. It is immunologically mediated via the hypersensitivity type I mechanism, which is primarily elicited by the immunoglobulin E (IgE)-linking allergen-induced imbalance of the Th2/Th1 immune response. Owing to the limited efficacy of current medications, probiotics have received attention for their potential in preventing and ameliorating AR. Methods In this study, a Lacticaseibacillus paracasei strain, GOLDGUTLpc969 (Lpc969), isolated from the feces of healthy adults, was proven to be effective in preventing AR by LPA-induced RBL-2H3 in-vitro and OVA-induced AR mice in-vivo evaluation. Results The strain significantly attenuated the release of histamine and degranulation in LPS-induced RBL-2H3 cells. In the OVA-induced AR mice, L. paracase i GOLDGUT-Lpc969 also exhibited a significant decrease in disease indicators such as the disease activity index (DAI score), serum IgE, and serum histamine. Treatment with L. paracasei GOLDGUT-Lpc969 led to significant suppression of the Th2-related cytokines IL-4, IL-5, IL-6, IL-13, and TNF-α in the serum of mice. Discussion Furthermore, a comparison of the genomes of three previously reported AR-effective L. paracasei strains (including GOLDGUTLpc969) and one non-effective L. paracasei strain revealed that the gene K03671 may play a key role in alleviating AR symptoms. In conclusion, this study highlights the efficacy of L. paracasei GOLDGUT-Lpc969 in AR prevention by suppressing the Th2 immune response and proposes the potential involvement of the functional gene K03671 in ameliorating AR symptoms. Therefore, L. paracasei GOLDGUT-Lpc969 shows promise as a probiotic for preventing AR.