An interventional study of Yeast Postbiotics and Placebo in Allergic Rhinitis, sponsored by LanZhou University. Not yet recruiting at 1 site in China. Open to participants aged 18 Years to 35 Years. Per ClinicalTrials.gov, last updated 2025-07-23.
Sponsored by LanZhou University · Not applicable, Interventional, and Treatment
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.
Allergic rhinitis (AR) is a chronic, non-infectious inflammatory disease of the nasal mucosa mediated by immunoglobulin E (IgE) in atopic individuals after exposure to allergens. Typical clinical manifestations include paroxysmal sneezing, clear nasal discharge, nasal itching, and nasal congestion, often accompanied by itchy eyes, tearing, sleep disturbances, and decreased quality of life. AR is one of the most common chronic nasal diseases in clinical practice, affecting approximately 10%-20% of the global population, and has been recognized by the World Health Organization as a major public health issue.
This study is a randomized, double-blind, placebo-controlled human intervention trial among university students with persistent allergic rhinitis symptoms. It aims to evaluate the efficacy of yeast postbiotics in improving persistent AR symptoms and to explore the potential mechanisms through which yeast postbiotics may alleviate AR symptoms by modulating the gut microbiota. A total of 80 volunteers with persistent AR symptoms will be recruited and randomly assigned to the yeast postbiotic intervention group (n = 40) or the placebo group (n = 40). Both participants and investigators will be blinded to group allocation. The randomization information will only be accessible to the study designers, and all interventions and samples will be coded to prevent unblinding. If a participant experiences a serious adverse event due to the intervention, unblinding will be performed and the participant will be withdrawn from the study During the intervention period, participants in the intervention group will take two capsules of yeast postbiotics daily, each containing 250 mg of yeast postbiotics along with appropriate amounts of maltodextrin and silicon dioxide. The placebo group will take two capsules per day of an identically appearing placebo, which contains only maltodextrin and a small amount of silicon dioxide. All participants will take the capsules once daily after meals with warm water. All participants will complete a daily Total Nasal Symptom Score (TNSS) and report any adverse events. Follow-ups will be conducted at Week 0, Week 4, and Week 12, including questionnaire assessments (VAS, RQLQ), dietary surveys, anthropometric measurements (height, weight, body fat percentage), and biological sample collection (blood, urine, saliva, and stool). A saliva sample will also be collected at Week 2.
The primary outcome of this study is TNSS. Secondary outcomes include: Visual Analogue Scale (VAS), Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), Serum specific IgE (sIgE), Secretory IgA (sIgA), Inflammatory cytokines (IFN-γ, IL-4, IL-10, IL-6, and TNF-α), Gut microbiota composition, Serum biochemical indicators (CRP, ALT/AST, BUN/Cr). Statistical analysis will be conducted using SAS 9.4 software. Continuous variables will be expressed as mean ± standard deviation, and ordinal variables as proportions. T-tests and Kruskal-Wallis rank-sum tests will be used to compare continuous variables. Chi-square tests or Fisher's exact tests will be used for categorical variables. A p-value \< 0.05 will be considered statistically significant. For outcome variables measured at multiple time points (e.g., VAS scores, cytokine levels at Weeks 0, 4, and 12), linear mixed-effects models (LMMs) will be constructed to assess the effects of time, group, and interaction, and to compare the trends across different time points between the intervention and control groups.
717 studies on the registry are indexed under Rhinitis, Allergic; 94 are open to participants now.
This study's planned enrollment of 80 is above the median of 68 across 552 interventional studies indexed under Rhinitis, Allergic.
Browse Rhinitis, Allergic studies →LanZhou University is the lead sponsor of 27 studies on the registry; 13 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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
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
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.
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.
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.
Time frame: Through intervention completion (Week 0 to Week 12)
Visual Analogue Scale (VAS)
A 10 cm straight-line scale where 0 represents "no symptoms" and 10 represents "worst imaginable symptoms." Participants mark a point on the line based on their subjective perception. It is used to evaluate the overall severity and frequency of allergic rhinitis (AR) symptoms.
Time frame: Baseline week 4 week 12
Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ)
A validated 28-item questionnaire covering seven domains: daily activities, sleep, nasal symptoms, ocular symptoms, emotional impact, practical problems, and environmental exposure. Each item is scored from 0 to 6; higher scores indicate greater impairment. Changes from baseline to post-intervention scores are used to evaluate improvements in quality of life.
Time frame: Baseline week 4 week 12
Serum Specific IgE (sIgE)
Measured using Fluorescence Enzyme Immunoassay (FEIA), such as ImmunoCAP, to detect IgE antibodies specific to common allergens. A result ≥0.35 kU/L is considered positive, indicating sensitization. It reflects the individual's allergic status and changes over time.
Time frame: Baseline week 4 week 12
Secretory IgA (sIgA)
Measured in fecal and saliva samples using ELISA kits. sIgA is an indicator of mucosal immune function and plays a role in first-line defense against pathogens.
Time frame: Baseline week 2 week 4 week 12
IFN-γ
A signature cytokine of Th1-type immune responses, IFN-γ plays a critical role in activating macrophages, enhancing antigen presentation, and promoting cellular immunity. Fasting plasma levels of IFN-γ are measured using high-sensitivity ELISA kits.
Time frame: Baseline week 4 week 12
IL-4
IL-4 is central in the pathogenesis of allergic diseases such as asthma and allergic rhinitis, contributing to eosinophilic infiltration and IgE production. Fasting plasma levels of IL-4 are measured using high-sensitivity ELISA kits.
Time frame: Baseline week 4 week 12
IL-10
An anti-inflammatory cytokine that modulates immune responses by inhibiting the synthesis of pro-inflammatory cytokines. Fasting plasma levels of IL-10 are measured using high-sensitivity ELISA kits.
Time frame: Baseline week 4 week 12
IL-6
A pleiotropic cytokine involved in both pro-inflammatory and anti-inflammatory processes. It plays a role in acute-phase responses, B-cell differentiation, and chronic inflammation. Fasting plasma levels of IL-6 are measured using high-sensitivity ELISA kits.
Time frame: Baseline week 4 week 12
TNF-α
TNF-α is a central pro-inflammatory cytokine involved in the initiation and amplification of inflammation. It plays a major role in systemic inflammation and is implicated in numerous inflammatory and autoimmune conditions. Fasting plasma levels of TNF-α are measured using high-sensitivity ELISA kits.
Time frame: Baseline week 4 week 12
C-reactive protein (CRP )
CRP is an acute-phase reactant produced by the liver in response to inflammation. Elevated CRP levels serve as a sensitive, though non-specific, marker of systemic inflammatory activity. CRP levels are measured using an automated biochemical analyzer.
Time frame: Baseline week 4 week 12
ALT/AST
ALT and AST are hepatic enzymes that reflect liver function. Elevated levels are indicative of hepatocellular injury or inflammation. ALT/AST levels are measured using an automated biochemical analyzer.
Time frame: Baseline week 4 week 12
BUN/Cr
BUN and creatinine are metabolic waste markers used to evaluate kidney function. Abnormal levels may indicate renal impairment. The BUN/Cr ratio is useful in distinguishing between prerenal and renal causes of dysfunction. BUN/Cr levels are measured using an automated biochemical analyzer.
Time frame: Baseline week 4 week 12
Gut Microbiota Composition
Fecal microbiota is analyzed using 16S rRNA gene amplicon sequencing to evaluate microbial diversity (α/β diversity), relative abundance of dominant taxa, and ecological shifts in response to intervention.
Time frame: Baseline week 4 week 12
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: No
Start is estimated for Jul 2025; primary completion for Dec 2026, 17 months later.
Of 66 non-industry interventional studies with no phase under Rhinitis, Allergic, half reached primary completion within 13 months of starting (the median), counting those still running; a quarter within 6 and three quarters within 28. This study's planned 17 months is above that.
Counting every sponsor, half of 87 studies reached it within 11 months; a quarter within 4 and three quarters within 27.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Jul 2025. You cannot join it, but the record below documents what was studied.
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LanZhou University