Overview

The goal of this clinical trial is to learn if a probiotic formulation consisting of multiple bacterial strains has a positive effect on the quality of life of participants with chronic perennial allergic rhinitis symptoms. The researchers will also study whether the probiotic formulation influences the symptoms of allergic rhinitis. Participants with allergies to house dust mite, cats and/or dogs will be included in the study.

The main questions it aims to answer are:

Does the probiotic formulation have an impact of the quality of life of the participants? Does the probiotic formaluation have an effect on the severity of the symptoms of allergic rhinitis? Are there differences in the effects depending on the allergies the participants have?

Researchers will compare the probiotic formulation to a placebo (a substance that contains no probiotic bacteria but looks, smells, and tastes the same) to see if the probiotic formulation improves the quality of life of participants with chronic allergic rhinitis. In addition, also a GI symptom questionnaire will be filled in by the participants weekly

Participants will visit the clinic for the screening, and at the start, and at the end of the intervention for checkups and sampling. During the intervention they will take the probiotic formulation or a placebo twice every day for 12 weeks. They will keep a diary of their symptoms and note whenever they use anti-histamines and every two weeks they will fill in a questionnaire about their quality of life.

Eligibility

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