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NCT Number: NCT07157462

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

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.

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Key information

Conditions

Perennial Allergic Rhinitis Dust Mite Allergy Hypersensitivity Hypersensitivity, Immediate Immune System Diseases Nose Diseases Otorhinolaryngologic Diseases Respiratory Hypersensitivity Respiratory Tract Diseases Rhinitis Rhinitis, Allergic Rhinitis, Allergic, Perennial

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

ALYATEC clinical center

Strasbourg, Alyatec, 67000, France

Location status: Recruiting

Location contact

Alina GHERASIM, MD

PRINCIPAL_INVESTIGATOR

Nathalie Domis, Ph.D

CONTACT

[email protected]

+33 (0)367680090

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Multi-species probiotic powder for oral solution. Dietary supplement containing six bacterial strains (Lactobacillus and Bifidobacterium species)

Dietary Supplement

The probiotic powder is provided in sachets. The Participants dissolve the powder in water and ingest twice daily for 12 weeks.

Placebo Powder for Oral Solution

Dietary Supplement

The placebo powder is provided in sachets. The Participants dissolve the powder in water and ingest twice daily for 12 weeks.

Primary outcomes

  1. The primary efficacy endpoint is the change in the global score of the mini-Rhinoconjunctivitis Quality of Life Questionnaire (mini-RQLQ) from baseline to week 12 of intervention

    Time frame: From baseline to 12 weeks of intervention

    An improvement on quality of life is considered clinically meaningful when improved with ≥0.7 points in global and domain-specific mini-RQLQ scores between intervention and placebo

Secondary outcomes

  1. The impact of intervention in rhino conjunctivitis quality of life will be assessed by the changes in global and domain-specific mini-RQLQ scores from baseline to week 12 of intervention every two weeks.

    Time frame: Every two weeks from baseline to end of treatment at 12 weeks

  2. The proportion of participants reporting a clinical relevant improvement on quality of life in global and domain-specific mini-RQLQ scores between intervention and placebo

    Time frame: From baseline to end of treatment at 12 weeks

    The proportion of participants reporting a clinical relevant improvement on quality of life will be assessed by the difference in proportion of participants achieving a clinically meaningful improvement (≥0.7 points) in global and domain-specific mini-RQLQ scores between intervention and placebo

  3. The proportion of participants reporting a clinical relevant improvement on allergic rhinoconjuctivitis symptoms in global and domain-specific TSS scores between intervention and placebo

    Time frame: From baseline to end of treatment at 12 weeks

    The proportion of participants reporting a clinical relevant improvement on allergic rhinoconjuctivitis symptoms will be assessed by the difference in proportion of participants achieving a clinically meaningful improvement (≥20%) in global and domain-specific TSS scores between intervention and placebo

  4. The impact of a multispecies probiotic formulation on allergic rhinoconjunctivitis severity will be assessed by the difference in TSS mean (global and per item) between intervention and placebo over 12 weeks.

    Time frame: From baseline to end of treatment at 12 weeks, daily

  5. The impact of a multispecies probiotic formulation on allergic rhinoconjunctivitis severity with established perennial allergies will be assessed as the change in the global score of the TSS from baseline to week 12 of intervention.

    Time frame: From baseline to end of treatment at 12 weeks

  6. Differences in TSS will be analysed in subgroups of participants based on type of allergy

    Time frame: From baseline to end of treatment at 12 weeks, daily

    Differences in TSS will be analysed in subgroups of participants based on type of allergy (HDM, HDM+Cat, HDM+Cat+Dog, Cat, Cat+Dog and Dog)

  7. Differences in TSS will be analysed in subgroups of participants based on allergy pattern

    Time frame: From baseline to end of treatment at 12 weeks, daily

    Differences in TSS will be analysed in subgroups of participants based on different allergy pattern (perennial vs perennial with seasonal allergies)

  8. Differences in TSS will be analysed in subgroups of participants based on baseline severity of TSS score

    Time frame: From baseline to end of treatment at 12 weeks, daily

    Differences in TSS will be analysed in subgroups of participants based on baseline severity as stratified by TSS scores as follows: 0-6 = mild, 7-12=moderate, 13-18 =moderate/severe, and 19-24= severe

  9. Differences in mini-RQLQ will be analysed in subgroups of participants based on type of allergy

    Time frame: From baseline to end of treatment at 12 weeks, two weekly

    Differences in mini-RQLQ will be analysed in subgroups of participants based on type of allergy (HDM, HDM+Cat, HDM+Cat+Dog, Cat, Cat+Dog and Dog)

  10. Differences in mini-RQLQ will be analysed in subgroups of participants based on allergy pattern

    Time frame: From baseline to end of treatment at 12 weeks, two weekly

    Differences in mini-RQLQ will be analysed in subgroups of participants based on on different allergy pattern (perennial vs perennial with seasonal allergies)

  11. Differences in mini-RQLQ will be analysed in subgroups of participants based on baseline severity of mini-RQLQ

    Time frame: From baseline to end of treatment at 12 weeks, two weekly

    Differences in mini-RQLQ will be analysed in subgroups of participants based on baseline severity as stratified by mini-RQLQ as follows: 0-1.5, 1.5-2.5, 2.5-3.5, 3.5-4.5, >4.5

  12. Change in immune modulatory biomarkers (cytokines and IgE) at baseline compared to 12 weeks of intervention versus placebo

    Time frame: From baseline to end of treatment at 12 weeks

  13. Change in amount of blood cells at baseline compared to 12 weeks of intervention versus placebo

    Time frame: From baseline to end of treatment at 12 weeks

  14. Change in ratio of blood cell at baseline compared to 12 weeks of intervention versus placebo

    Time frame: From baseline to end of treatment at 12 weeks

  15. Change in rescue medication use (antihistamines) will be expressed as a percentage of the completed daily diary entries over the 12 weeks intervention period

    Time frame: From baseline to end of treatment

  16. Reduction in gastro-intestinal complaints will be assessed using the GSRS questionnaire after 12 weeks intervention versus placebo and across weekly time points

    Time frame: From baseline to end of treatment at 12 weeks and weekly between those timepoints

  17. Reduction in allergic symptoms other than rhinitis (eczema, food allergy and intolerance) using Non-rhinoconjunctivitis allergy Questionnaire over the 12 weeks intervention versus placebo

    Time frame: From baseline to end of treatment at 12 weeks

  18. Change in fecal microbiome profile or metabolites production (e.a SCFA and bile acids) will be analyzed after 12 weeks intervention versus placebo

    Time frame: From baseline to end of treatment at 12 weeks

Other outcomes

  1. Correlation between change from baseline in GSRS total score and changes in gut microbiome composition and fecal metabolite concentrations at Week 12

    Time frame: From baseline to end of treatment at 12 weeks

    Associations between gastrointestinal symptom changes, as measured by the Gastrointestinal Symptom Rating Scale (GSRS; 15 items, 7-point Likert scale), and changes in gut microbiome composition and fecal metabolite concentrations will be explored. Microbiome profiling will be performed using 16S rRNA sequencing of stool samples, and metabolite analysis will include short-chain fatty acids (SCFAs), bile acids, and other metabolites identified through untargeted metabolomics. Correlation analyses (e.g., Spearman's rank correlation) and/or linear regression models will be applied. Additional multivariate or network analyses may be used to explore complex interaction patterns. These analyses are exploratory and hypothesis-generating; no formal adjustment for multiple testing will be applied.

Study contacts

Contact information is provided by the study sponsor or research team.

Kitty Maassen, PhD

CONTACT

[email protected]

+31647210612

Maria Stolaki, MSc

CONTACT

[email protected]

Sponsors and collaborators

Lead sponsor

Winclove B.V.

Industry

Collaborators

  • Alyatec

Registry information

Acronym: AllerGo

Important dates

Study start
2025
Primary completion
2026
Study completion
2026
First posted
Sep 5, 2025
Registry last updated
Nov 24, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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