Study of the Effects and Mechanisms of Yeast Postbiotics on Persistent Allergic Rhinitis Symptoms

NCT07079748 | Not Yet Recruiting

• 1 other identifier: IRB25041501
• Study Type: interventional
• Target: 80
• Locations: 1 country
• Sites: 1

Brief Summary

This study is designed as a randomized, double-blind, placebo-controlled human intervention trial among university students with persistent allergic rhinitis (AR) symptoms. The aim is to evaluate the effectiveness of yeast postbiotics in alleviating persistent AR symptoms and to explore the potential mechanisms by which yeast postbiotics modulate the gut microbiota to improve AR-related outcomes. A stratified randomization method will be applied to assign participants into the yeast postbiotic group and the placebo group. Stratification will be based on(1) Sex (male/female), and (2) Physician-diagnosed AR status (yes/no, based on self-reported clinical history), ensuring comparability between the two groups. During the intervention period, participants in the yeast postbiotic group will take two capsules of yeast postbiotic supplements daily after meals, while the placebo group will take two placebo capsules, identical in appearance and composition except without the active ingredients. The total study duration is 15 weeks, including a 1-week run-in period, 12-week intervention, and 2-week follow-up after the intervention. All participants will be asked to complete a daily nasal symptom score (TNSS) and report any adverse events. At week 0, week 4, and week 12, follow-up assessments will be conducted, including: symptom and quality-of-life questionnaires (e.g., VAS, RQLQ), dietary intake surveys, anthropometric measurements (height, weight, body fat percentage), and biological sample collection (including blood, urine, saliva, and feces). Additionally, saliva samples will be collected specifically at week 2 of the intervention to assess mucosal immune markers.

Conditions

Allergic Rhinitis

Keywords

Allergic Rhinitis; Yeast Postbiotics

Outcome Measures

Primary Outcomes (1)

• Total Nasal Symptom Score (TNSS)

  A scoring system to evaluate the severity of four nasal symptoms: nasal itching, sneezing, rhinorrhea, and nasal congestion. Each symptom is rated on a scale of 0 to 3, with a total score ranging from 0 to 12. Higher scores indicate more severe symptoms.

  Through intervention completion (Week 0 to Week 12)

Secondary Outcomes (13)

• Visual Analogue Scale (VAS)

  Baseline week 4 week 12

• Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ)

  Baseline week 4 week 12

• Serum Specific IgE (sIgE)

  Baseline week 4 week 12

• Secretory IgA (sIgA)

  Baseline week 2 week 4 week 12

• IFN-γ

  Baseline week 4 week 12

Study Arms (2)

Yeast Postbiotic Group

EXPERIMENTAL

Participants in the intervention group will take two capsules of yeast postbiotics daily after meals, with each capsule containing 250 mg of yeast postbiotics, along with maltodextrin and silicon dioxide.

Dietary Supplement: Yeast Postbiotics

Placebo Group

PLACEBO COMPARATOR

Participants in the placebo group will take an equal number of placebo capsules, identical in dosage form, taste, appearance, and packaging. The placebo contains only maltodextrin and a small amount of silicon dioxide. All participants will take two capsules once daily, swallowed with warm water after meals.

Dietary Supplement: Placebo

Interventions

Yeast Postbiotics DIETARY_SUPPLEMENT

Participants in the intervention group will take two capsules of yeast postbiotics daily after meals, with each capsule containing 250 mg of yeast postbiotics, along with maltodextrin and silicon dioxide.

Yeast Postbiotic Group

Placebo DIETARY_SUPPLEMENT

Participants in the placebo group will take an equal number of placebo capsules, identical in dosage form, taste, appearance, and packaging. The placebo contains only maltodextrin and a small amount of silicon dioxide. All participants will take two capsules once daily, swallowed with warm water after meals.

Placebo Group

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Aged between 18 and 35 years;
• Meeting the symptom criteria for persistent allergic rhinitis (AR) as defined in the Chinese Guidelines for Diagnosis and Treatment of Allergic Rhinitis (2022, Revised Edition): (1) Symptoms: Two or more of the following-paroxysmal sneezing, watery rhinorrhea, nasal itching, and nasal congestion-lasting continuously or cumulatively for at least 1 hour per day; ocular symptoms such as tearing, itching, and redness may also be present; (2) Persistent AR: Symptoms occur on ≥4 days per week and persist for ≥4 consecutive weeks;
• No use of probiotics, prebiotics, synbiotics, antihistamines, corticosteroids, or immunosuppressants within 1 month prior to screening;
• Willing and able to maintain usual physical activity levels and dietary patterns during the study;
• Able and willing to sign the informed consent form voluntarily.

You may not qualify if:

• Use of antibiotics, osmotic laxatives (e.g., magnesium sulfate, lactulose), anthraquinone-containing agents (e.g., rhubarb, aloe, senna), or gastrointestinal motility-promoting drugs (e.g., metoclopramide, domperidone, cisapride) within 1 month prior to screening;
• Diagnosed with non-allergic rhinitis (e.g., vasomotor rhinitis, infectious rhinitis, hormonal rhinitis, drug-induced rhinitis), or with nasal polyps, severe nasal septum deviation, cerebrospinal fluid rhinorrhea, or aspirin-exacerbated respiratory disease (AERD);
• Patients with uncontrolled allergic comorbidities, including sinusitis, otitis media, allergic asthma, or atopic dermatitis;
• History of serious gastrointestinal diseases (e.g., severe diarrhea, inflammatory bowel disease), or gastrointestinal endoscopy within the past month;
• Diagnosed with congenital genetic disorders, primary immunodeficiency diseases, severe systemic illnesses, or malignancies;
• Pregnant or lactating women, or women with plans to conceive during the study period.

Sponsors & Collaborators

• LanZhou University: lead

Study Sites (1)

School of Public Health, Lanzhou University

Lanzhou, Gansu, China

Location

MeSH Terms

Conditions

Rhinitis, Allergic

Condition Hierarchy (Ancestors)

Rhinitis; Nose Diseases; Respiratory Tract Diseases; Respiratory Hypersensitivity; Otorhinolaryngologic Diseases; Hypersensitivity, Immediate; Hypersensitivity; Immune System Diseases

Central Study Contacts

Xiaoqin Li, Dr.Prof.

CONTACT

+86 15927366423; lixiaoqin@lzu.edu.cn

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor, School of Public Health, Lanzhou University

Study Record Dates

• First Submitted: July 4, 2025
• First Posted: July 23, 2025
• Study Start: July 25, 2025
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: July 23, 2025

Record last verified: 2025-07

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)