Lacticaseibacillus Rhamnosus LRa05 for Alleviating Allergic Rhinitis

This clinical trial aims to evaluate the efficacy and safety of Lactobacillus rhamnosus LRa05 in alleviating allergic rhinitis symptoms and its effects on gut microbiota in 70 adults aged 18-60 years. Participants will receive probiotic powder or placebo daily for 4 weeks. Allergic rhinitis symptoms and quality of life will be assessed, while stool and blood samples will be collected to evaluate changes in gut microbiota and immune-related markers.

Inclusion Criteria: 1. Voluntarily, in writing, sign the informed consent form, agreeing to participate in this study; 2. Capable of completing the study according to the test protocol requirements; 3. Age between 18 to 60 years old; 4. Meet the diagnostic criteria for allergic rhinitis established in the "Chinese Guidelines for the Diagnosis and Treatment of Allergic Rhinitis (Revised Edition 2022)"; 5. Symptoms: Presence of two or more symptoms such as sneezing, watery rhinorrhea, nasal itching, and nasal congestion, with symptoms lasting or accumulating for more than one hour per day, possibly accompanied by eye itching, tearing, and redness, and other ocular symptoms; 6. Signs: Nasal mucosa is pale and edematous, possibly with watery secretions; 7. Laboratory tests: At least one allergen detected by skin prick test and/or specific IgE positivity in serum; 8. No use of antihistamines, corticosteroids, or immunosuppressants in the month before screening; 9. No history of heart, liver, kidney, nervous system, mental disorders, or metabolic abnormalities. Exclusion Criteria: 1. Use of medications affecting the gut microbiota (including antimicrobial drugs, probiotics, intestinal mucosal protective agents, traditional Chinese patent medicines, etc.) for more than 1 week within 1 month prior to screening; 2. Patients with coexisting pulmonary tuberculosis; 3. Those with coexisting allergic asthma; 4. Individuals with nasal polyps or severe nasal septal deviation; 5. Patients with severe systemic diseases or malignant tumors; 6. Those with congenital genetic diseases or congenital immunodeficiency diseases; 7. Regular use of probiotics or prebiotics within 6 months prior to the screening period; 8. Individuals with severe gastrointestinal diseases (including severe diarrhea, inflammatory bowel diseases, etc.); 9. Those with metabolic syndrome (including obesity, dyslipidemia, hypertension, diabetes, etc.); 10. Individuals with sinusitis, otitis media, or respiratory tract infections; 11. Those allergic to any components of the probiotics used in this trial; 12. Women who are pregnant or breastfeeding, or those planning to conceive in the near future; 13. Subjects who discontinue the test sample or add other medications midway, making it impossible to determine efficacy or with incomplete information; 14. Those who have recently consumed items similar to the test product, affecting the judgment of the results; 15. Subjects who, due to their own reasons, cannot participate in the trial; 16. Any other subjects deemed unsuitable to participate by the investigators.