Investigation of the Effects of a Multispecies Probiotic Formulation on Perennial Allergic Rhinitis

Inclusion Criteria: * Adults aged ≥18 years * Willing and able to provide informed consent in French * Persistent perennial allergic rhinitis induced by a least one perennial allergen in the last two years. * Positive skin prick test ≥5 mm for any of the following allergens: cat, dog and mites * Mean global score of miniRQLQ ≥ 2 * TSS score of at least 7 * Willing to discontinue consumption of fermented foods, probiotics (e.g., yogurts with live, active cultures or supplements), prebiotics or immune-enhancing supplements (e.g., Echinacea or fish oil). * Agreement on not starting new medication during the intervention (rescue medication excepted) * Women of childbearing potential with a negative pregnancy test throughout the study period and highly effective contraception: oral contraceptives, condom with spermicide, intrauterine device, bilateral tubal ligation, vasectomized partner Exclusion Criteria: * Non-allergic rhinitis * Use of any prohibited medication (any systemic corticosteroids, androgens such as testosterone, or high doses of anti-inflammatory drugs: i.e., aspirin in doses 600 mg/d regularly) at the time of enrolment * Use of other probiotics-containing and prebiotics-containing products during the intervention period and 4 weeks before study start * Use of any antibiotics 6 weeks before randomization * Nasal polyposis * Currently enrolled in another intervention study (except observational studies) * Critically or terminally ill or admitted to the ICU * Had received chemotherapy or other immune-suppressing therapy within the previous year. * Other conditions that according to the investigator might interfere with the evaluation of the study objectives * Patients being treated for or had any of the following physician-diagnosed diseases or conditions: HIV; immune modulating diseases (autoimmune disease, hepatitis, cancer, etc.); kidney disease; pancreatitis; pulmonary disease; hepatic or biliary disease; or gastrointestinal diseases or conditions, such as diverticulitis, ulcerative colitis, Crohn's disease, Celiac disease, short bowel disease, ileostomy, or colostomy, but not including gastroesophageal reflux disease, * Subjects with a low compliance rate (appreciated by the investigator) during the run-in period