Efficacy and safety of a particulate yeast β-glucan preparation in the treatment of seasonal allergic rhinitis (BETALL): a randomized placebo-controlled crossover trial protocol

Efficacy and safety of a particulate yeast β-glucan preparation in the treatment of seasonal allergic rhinitis (BETALL): a randomized placebo-controlled crossover trial protocol | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Efficacy and safety of a particulate yeast β-glucan preparation in the treatment of seasonal allergic rhinitis (BETALL): a randomized placebo-controlled crossover trial protocol David Briskey, Janice Pellow, Gemma Beatson, Annie Tremblay, Amanda Rao, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7047821/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 17 Apr, 2026 Read the published version in Trials → Version 1 posted 5 You are reading this latest preprint version Abstract Background Allergic rhinitis (AR) has been shown to be a significant global health burden. Despite the existence of pharmacological treatments, mainly antihistamines, nasal corticosteroids, and decongestants, many individuals with seasonal allergies turn to alternative herbal medicines and nutritional supplements for the management of symptoms. The primary objective of the current study is to evaluate the efficacy and safety of a 500 mg daily dose of a yeast β-glucan preparation (M-Gard ® ) on reducing the severity of nasal and ocular symptoms in a population with seasonal AR. Methods This randomized placebo-controlled crossover trial will evaluate the effect of 500 mg of a 14-day M-Gard ® or placebo (microcrystalline cellulose) supplementation period on the relief of grass pollen-induced AR symptoms in 20 generally healthy adults (18–65 years) with a history of recurrent seasonal AR. Participants will consume M-Gard ® or Placebo during 14 days, starting 12 days before the antigen challenge and ending 2 days after. Each supplementation periods will be separated by a 2-week washout period. Allergy symptoms will be assessed at baseline (Day 0) and on Days 12–14 using a Visual Analogue Scale (VAS) rating AR symptom severity as primary outcome (nasal congestion, sneezing, itchy nose, runny nose and watery eyes) and validated questionnaires as secondary outcomes (Reflective Total Nasal Symptom Scores (rTNSS), Reflective Total Ocular Symptom Scores (rTOSS), Rhinitis Control Scoring System (RCSS), and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ)). In addition, onset of relief, use of rescue medication, and adverse events will be monitored for up to 2 days after the grass allergen challenge. Peak nasal inspiratory flow (PNIF) and pathology markers (cytokines, histamine, tryptase, and allergen-specific IgE) will also be measured. All outcomes will be analyzed as the change from baseline and between-group comparisons will be assessed using appropriate models. Discussion The study hypothesis is that M-Gard ® supplementation will be more effective than placebo in reducing AR symptoms. This research will strengthen the evidence base supporting the use of M-Gard ® as a supplement for the management of AR. Trial registration NCT06907680 Postbiotic yeast β-glucan allergy allergic rhinitis grass pollen M-Gard® Figures Figure 1 Administrative information Note : the numbers in curly brackets in this protocol refer to SPIRIT checklist item numbers. The order of the items has been modified to group similar items (see http://www.equator-network.org/reporting-guidelines/spirit-2013-statement-defining-standard-protocol-items-for-clinical-trials/). Title {1} Efficacy and safety of a particulate β-glucan preparation in the treatment of seasonal allergic rhinitis (BETALL): a randomized placebo-controlled crossover trial protocol. Trial registration {2a and 2b}. clinicaltrials.gov NCT06907680 BETALL Protocol version {3} Protocol Number 202502222 V2.0 27 May 2025 Funding {4} The funding for this trial was received from Lallemand Bio-Ingredients. Author details {5a} David Briskey 1 , Janice Pellow 1 , Gemma Beatson 1 , Annie Tremblay 2 , Thomas A. Tompkins 2 , Amanda Rao 1 * 1 RDC Clinical, Brisbane, Queensland, Australia 2 Lallemand Bio-Ingredients, Montreal, QC, Canada Name and contact information for the trial sponsor {5b} Thomas A. Tompkins Ph.D Lallemand Bio-Ingredients 1620, rue Prefontaine Montreal, Quebec H1W 2N8 Canada [email protected] Role of sponsor {5c} AT and TAT, are employees of Lallemand Bio-Ingredients. TAT was involved in the study design presented herein. AT and TAT are not involved in the conduct, management, analysis, or interpretation of the data. The sponsor will be involved in the decision to submit trial results for publication. Introduction Background and rationale {6a} Allergic rhinitis (AR) is an atopic condition that is the result of a type 1 hypersensitivity reaction occurring in response to aeroallergens such as pollens from trees, grass, and weeds, or mould spores. Characteristic symptoms include rhinorrhea, sneezing, nasal congestion, pruritis of the nose, and ocular symptoms such as increased lachrymation, redness and pruritis (1). AR can be classified as either seasonal (SAR) or perennial (PAR), with around 40% of cases having features of both. According to the 2022 National Health Survey, AR affects around 23.9% of the Australian population (2). Beta-glucans are groups of polysaccharides found in the cell walls of bacteria, fungi, algae and cereals, and are composed of D-glucose monomers linked by specific glycosidic bonds (3). The shape and structure (i.e., branching characteristics), and molecular weight of β-glucans determine their solubility, bioavailability, and biological activity. Beta-1,3-glucans occur in bacteria, β-1,3/1,4-glucans are found in cereals and marine algae, while β-1,3/1,6-glucans occur mainly in yeasts (long D-glucose chains) and macrofungi (shorter D-glucose chains). Beta-glucans supplements offer several health benefits, including immunomodulatory, anticancer and antimicrobial effects (4). M-Gard ® Particulate EW (hereafter referred to as M-Gard ® ) is a purified bioactive β-1,3/1,6- glucan supplement, isolated from the cell walls of baker’s yeast ( Saccharomyces cerevisiae ). Another study evaluated the effects of a daily dose of 500 mg a day of yeast β-glucan dietary supplementation given for 6 weeks on the antibody response to the seasonal influenza vaccine with positive results (5). The primary outcome of the current study will evaluate the efficacy of a 500 mg daily dose of M-Gard ® on reducing the severity of nasal and ocular symptoms in individuals with seasonal AR. Secondary measures include AR control, peak nasal inspiratory flow, quality of life, use of rescue medications, blood markers (cytokines, histamine, tryptase, and allergen-specific IgE) and safety markers (FBC & E/LFT) via blood test and vital signs (blood pressure, heart rate, oxygen saturation, temperature). Objectives {7} The aim of this study is to assess the safety and efficacy of M-Gard ® supplementation at 500 mg daily at reducing AR symptoms in generally healthy adults upon exposure to grass pollen. It is hypothesised that M-Gard ® supplementation will be more effective than placebo in decreasing the number of symptoms or their severity in participants with AR. Trial design {8} Figure 1A shows the 14-day supplementation period organization and Figure 1B shows the crossover design organization and complete timeline. Briefly, the 6-week, 2-arm, randomized, crossover study comprises 2 supplementation periods separated by a 2-week washout without any supplementation. Yeast mannan and control supplementation will be blinded and allocated in a 1:1 ratio. The primary aim of the study will assess the relief of AR symptoms, with the hypothesis that 500 mg of M-Gard ® daily for 2 weeks will be superior to the placebo. Methods: Participants, interventions and outcomes Study setting {9} This trial will be conducted at RDC Clinical, Level 3, 252 St Pauls Terrace, Fortitude Valley, Brisbane, Queensland. Eligibility criteria {10} The study will include generally healthy adults aged 18-65 years with a BMI 18-35kg/m2 and a history of recurrent seasonal allergic rhinitis. Inclusion will also require a positive radioallergosorbent test (RAST) results for grass allergy during screening. Participants must be able to provide informed consent, agree not to change their current diet and/or exercise routine during entire enrolment period and agree to not participate in another clinical trial during the study period. Potential participants will be excluded in case of serious illness (e.g., liver disease, kidney disease, heart disease, mood disorders, neurological disorders such as multiple sclerosis), unstable illness (e.g., diabetes and thyroid gland dysfunction). Other exclusion criteria will include: Current malignancy (excluding Basal Cell Carcinoma) or chemotherapy or radiotherapy treatment for malignancy within the previous 2 years, symptomatic perennial allergic rhinitis, non-allergic rhinitis, chronic respiratory conditions (e.g., asthma, chronic obstructive pulmonary disease), cognitive damage, acute illness experienced in the past 1 month, or any condition which in the opinion of the investigator makes the participant unsuitable for inclusion. Women attempting to conceive, pregnant or lactating will be excluded, as well as active smokers (nicotine or drug abuse), chronic past and/or current alcohol use (>21 alcoholic drinks per week), individuals allergic to any of the ingredients in the active or placebo formula, using medications that would affect the immune and/or the inflammatory response (e.g. immunotherapy, antihistamines (daily use), corticosteroids, mast cell stabilizers, leukotriene modifiers, and decongestants) or taking Coumadin (Warfarin), Heparin, Dalteparin, Enoxaparin or other anticoagulation therapy including low dose aspirin, tricyclic antidepressants, Clonidine and other central acting alpha-2-agonists, currently participating in any other clinical trial or who have participated in any other clinical trial during the past 1 month. Who will take informed consent? {26a} Potential participants will have a phone call meeting arranged with one of the trial coordinators at least 24 hours after receiving the participant information and consent form. During this call, participants will be screened against the inclusion and exclusion criteria and be given a full explanation of the trial and their requirements. Furthermore, participants will be given the opportunity to ask any questions, have information repeated and verified, and welcomed to consult with a family member or friend prior to providing consent. Following screening, potential participants who wish to enrol will be required to sign an electronic consent form to indicate their understanding and willingness to be included in the trial. Additional consent provisions for collection and use of participant data and biological specimens {26b} Not applicable. Interventions Explanation for the choice of comparators {6b} Microcrystalline cellulose (MCC) will be used as the placebo, as in other β-glucan studies because it effectively replicates the physical properties of β-glucans without the biological effects. It is non-digestible and inert; however, it still may be metabolized to a minor extent by the colonic microbiome. We will assess the impact of the MCC on microbiome composition. Intervention description {11a} SPIRIT guidance: Interventions for each group with sufficient detail to allow replication, including how and when they will be administered. The investigational product will be a purified yeast cell wall fraction obtained from Baker’s yeast ( Saccharomyces cerevisiae ), containing β-glucans (≥ 80%) and few mannoproteins (≤ 3,5 %) (M-Gard®, Lallemand Bio-Ingredients, Montreal, QC) provided as capsules, each containing 250 mg of M-Gard ® . Criteria for discontinuing or modifying allocated interventions {11b} During the trial, new information about the risks and benefits of the treatment may become known to investigators. If this occurs, participants will be advised as soon as practically possible about this new information so that they can reassess their willingness to be involved in the trial. In addition, an Investigator may discontinue a participant’s participation in the trial without participant consent based on the following criteria: • When there is an onset of a serious adverse event (SAE), and the Principal Investigator (PI) determines that the participant has to discontinue the study. • When significant AR symptoms are observed, and the PI determines that it is difficult for the participant to continue the study. • Protocol violation that in the opinion of the PI affects the data irreparably or continuous protocol violation e.g. failure to complete questionnaires, non-compliance with taking the study product based on the schedule in the protocol, or major changes in living conditions. The PI will then determine whether the participant has compromised reliability in completing the study. • When the participant is found not to be eligible after the start of the study or, due to new circumstances, no longer meets the listed inclusion or exclusion criteria. • When the participant does not comply with the instructions of the PI. • When the PI deems that the study is to be discontinued. • When medical consultant after case file review deems participant unfit to participate. • When participants start taking concomitant medications that may affect the outcome of the study. • The investigational product has unacceptable adverse effects / adverse drug reactions. • Any other reason at the discretion of the principal investigator or sponsor. Strategies to improve adherence to interventions {11c} Participants will be monitored for dosing compliance. At the completion of the trial, each participant will return unused investigational product to the clinic team where capsules will be counted. Compliance will be calculated by determining the number of dosage units taken divided by the number of dosage units expected to have been taken multiplied by 100. In the event of discrepancy between the information recorded and the amount of investigational product returned, use will be based on the product returned unless an explanation for loss of product has been provided. Non-compliance will be defined as 120% of their dose, as per randomisation schedule. Relevant concomitant care permitted or prohibited during the trial {11d} Participants will be asked to maintain their usual diet and physical activity patterns throughout the study and allowed to continue any prescription, over-the-counter (OTC), vitamins, minerals and/or herbal medicines that are not considered to affect the study outcomes. No other medications for the treatment of seasonal AR, other than the investigational product, will be permitted for the duration of the study. As the study will be conducted outside of the grass allergy season, it is expected that participants will not have AR symptoms or need rescue medication other than on the days of the nasal allergen challenge (NAC). The trial doctor will be monitoring participants’ symptoms during the NAC and will provide rescue medication as needed. Provisions for post-trial care {30} No post-trial care is anticipated. The study will involve generally healthy adult participants, and their participation is deemed to pose minimal risk. In case of an adverse event potentially related to the study, participants will receive follow-up care until recovery. Outcomes {12} The primary outcome is the relief of AR symptoms, including total and individual AR symptom severity measured by a visual analogue scale (VAS) of nasal congestion, sneezing, itchy nose, runny nose and watery eyes. Symptoms will be rated on a scale of 0 to 10 where 0 is "not troublesome at all" and 10 is "very troublesome". For each symptom, the difference in VAS scores between the M-Gard and placebo groups will be assessed using a paired t-test or Wilcoxon signed-rank test (depending on normality of data). Symptom severity at specific timepoints will also be compared between treatment periods (IP 1 vs. IP 2) using a mixed-effects model for repeated measures, controlling for baseline values and period effects. Participant timeline {13} The participants timeline and schedule of assessments is presented in Table 1. Once enrolled in the study, and having been confirmed as having a grass allergy with a positive RAST result, participants will attend an in-clinic session. Height, weight, BMI and vital signs (blood pressure, heart rate, temperature, O 2 saturation) will be measured and a baseline blood sample obtained. The participants will complete the baseline AR symptom severity VAS, rTNSS, rTOSS, RCSS and the RQLQ. Once the participant has been randomly allocated the first investigational product, they will take 1 capsule twice daily on days 1-11). Participants will be monitored for IP compliance, concomitant medication use, exercise and dietary changes, and adverse events at day 7. On day 12 participants will return to the RDC Clinic for a NAC test. The participants will take 1 capsule of IP twice daily as per usual. At the clinic, the participants will have their vital signs measured. They will be monitored for IP compliance, concomitant medication use, exercise and dietary changes, and adverse events. Participants will have a cannula inserted and a fasted blood sample will be taken to assess for safety markers. They will complete the VAS, rTNSS and rTOSS prior to undergoing the challenge. The NAC will be performed in the clinic by the trial doctor. Participants will be administered mixed grass allergen via a nasal spray, providing a standardised dose. Peak nasal inspiratory flow (PNIF) will be measured to assess for nasal patency and allergy symptoms will be rated via the VAS, rTNSS and rTOSS. Participants will be monitored by the trial doctor, in the clinic, for the next 2 hours. Adverse events will be monitored, and blood will be collected to test for serum levels of cytokines, histamine, tryptase, and allergen-specific IgE. Participants will be provided with rescue medications as needed, and their use will be recorded. Participants will also complete the RCSS and RQLQ. On days 13 and 14, participants will continue to take the study product, and allergy symptoms will be monitored remotely, by means of the AR symptom severity VAS, rTNSS, rTOSS, RCSS and RQLQ. Participants will be monitored for IP compliance, concomitant medication use, exercise and dietary changes, and adverse events on day 14. After a 2-week washout period (days 15-28), participants will return to the clinic on day 29 to repeat the baseline testing before starting the alternative product (days 30-40) and repeat the allergen testing (day 41) as per above. Allergy symptoms will be monitored on days 42 and 43. The washout period of 2 weeks is based on the methodology used by a published study testing consecutive interventional products, with 2-week washouts in-between, in a population with asthma (6). Sample size {14} Power was determined using G*Power (V3.1) using values from previously conducted studies by RDC Clinical and our experience at conducting trials of this nature. To detect a 40% change in VAS, 15 participants per group are required. To allow for dropouts and non-responders, up to 25 participants per group will be recruited. Recruitment {15} After reviewing the Study Summary Page, interested potential participants will be required to answer a few basic questions to do with the inclusion/exclusion criteria in order to register their interest. Those who register their interest will be provided with an electronic copy of the participant information and consent form (PICF) to read. Potential participants will have a phone call meeting arranged with one of the trial coordinators at least 24 hours after receiving the PICF. During this call, participants will be screened against the inclusion and exclusion criteria and be given a full explanation of the trial and their requirements. Furthermore, participants will be given the opportunity to ask any questions, have information repeated and verified, and welcomed to consult with a family member or friend prior to providing consent. Following screening, potential participants who wish to enrol will be required to sign an electronic consent form to indicate their understanding and willingness to be included in the trial. Assignment of interventions: allocation Sequence generation {16a} Randomisation will be conducted by someone not involved in the conduct of the trial. The randomisation code for the products will be generated by Random Allocation Software. Concealment mechanism {16b} All investigational product (active and placebo) will be packed in the same type of container and labelled identically except for the product number (based on the randomisation code). The product will be uniquely numbered and as each participant is enrolled, they will be given one of the numbered products. Trial participants will not know the order of what investigational product they will be taking. Unless medically necessary, only upon the completion of all sample analysis (including statistics) will the randomisation code be revealed. Implementation {16c} The Clinical Project manager, who is not associated with the conduct of the study will carry out the randomization by sealed envelope. The study coordinators will enroll the participants and, by opening the sealed envelopes, will assign the participants to their study arm. Assignment of interventions: Blinding Who will be blinded {17a} Trial participant, care provider, investigators and outcomes assessors will be blinded to the allocation sequence. Procedure for unblinding if needed {17b} It is not necessary to unblind a participant’s treatment assignment in most circumstances, even if an SAE has occurred, unless the Principal Investigator (PI) deems unblinding as a necessary step for participant safety. Hence, unless medically necessary, the randomisation codes will be revealed only upon the completion of all sample analysis (including statistics). Data collection and management Plans for assessment and collection of outcomes {18a} The methods for the collection of outcomes are described below: Height : measured by stadiometer in metres and without shoes. Weight : measured by scales in kg and without shoes. Blood pressure : measured by blood pressure machine in mmHG after sitting for 5 minutes. Heart rate : measured in BPM by blood pressure machine after sitting for 5 minutes. Temperature : measured in degrees Celsius by thermometer. O 2 saturation : measured in % by pulsoximeter. Allergic Rhinitis Symptom Severity Visual Analogue Scale (VAS): A self-reported tool that measures the severity of the following AR symptoms: nasal congestion, sneezing, nasal itching, runny nose, and watery eyes. These symptoms will be rated on a scale of 0 to 10 where 0 is “not troublesome at all” and 10 is “very troublesome”. Studies have shown that for AR, irrespective of the baseline VAS score, an improvement of 23 mm under therapy indicated effective treatment; an improvement of 30 mm is associated with improvements in QoL parameters. MACVIA ARIA defined AR control cut-offs are: >50: uncontrolled, 20–50: partly controlled, and <20: well controlled. A VAS has been shown to be a reliable and practical means to assess AR symptoms and AR control. Individual symptom severity scores and total allergic rhinitis severity scores will be calculated (7, 8). Reflective Total Nasal Symptom Scores (rTNSS): Self-reported questionnaire rating the severity of four nasal symptoms (runny nose, nasal congestion, itchy nose, and sneezing) on a four-point scale (0-3), where 0 = no symptoms, 1 = mild symptoms, 2 = moderate symptoms, and 3 = severe symptoms. The rTNSS is the sum of the scores for each of the nasal symptoms (from 0 to 12) (9). Reflective Total Ocular Symptom Scores (rTOSS): Self-reported questionnaire that is calculated as the sum of the participants’ scoring of the severity of three ocular symptoms (itching/burning, tearing/watering, and redness) on a scale of 0-3 where 0 = absent, 1 = mild, 2 = moderate, and 3 = severe). Rhinitis Control Scoring System (RCSS): A brief, validated, subject-completed tool including 5 items (sneezing, rhinorrhea, nasal obstruction, nasal pruritus, and conjunctivitis). Each symptom is rated on a 5-point scale depending on its intensity (none-10%, mild-8%, moderate-6%, severe-4%, very severe-2%) and its frequency (never-10%, rarely-8%, occasionally-6%, frequently-4%, very frequently-2%), which are assessed separately. The sum of the intensity score and the frequency score gives the global score (10). Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ): Self-reported questionnaire used measure the functional impairments that are most troublesome to participants because of their rhinoconjunctivitis. It consists of 28 questions in 7 domains (activity limitation, sleep problems, nose symptoms, eye symptoms, non-nose/eye symptoms, practical problems and emotional function). These are rated on a 7-point scale (0 = not impaired at all - 6 = severely impaired). The overall RQLQ score is the mean of all 28 responses and the individual domain scores are the means of the items in those domains (11). Blood markers to be tested: cytokines, histamine, tryptase, allergen-specific IgE. Safety will be evaluated via blood test and vital signs (blood pressure, heart rate, O 2 saturation, temperature). Blood sample: Cannulations and venepunctures will be conducted by a trained phlebotomist. Blood will be collected from an antecubital fossa vein (anterior side of the elbow) using single use needles and vacutainers (for one off draws – Baseline visits) or cannulation (for repetitive draws – NAC visits). Cannulation and Blood Draw: - Clean site with an alcohol swab - Insert cannula - Attach one-way valve to cannula - Apply sterile dressing/bandage to hold cannula securely in place - Test patency of cannula by drawing blood into a syringe. If no blood is drawn, the cannula is not in the vein correctly and will need to be repositioned. - Draw 1-2 mL of blood into a waste syringe and dispose - Draw required blood using a fresh syringe - Flush cannula with sterile saline (amount equivalent to total blood drawn) Following the completion of the blood draws the cannula and bandages will be removed, and cotton wool applied to the insertion site to stop any bleeding. This wool will remain in place for at least 5 minutes. Patency of the cannula will be maintained by flushing the cannula hourly with sterile saline regardless of if there is a blood draw or not. Venepuncture ( For one of the draws). - Clean site with an alcohol swab - Insert needle with vacutainer holder - Attach each vacutainer and draw a maximum of 10 mL of blood to each container (20 mL total) - Remove needle while applying cotton wool to site - Secure wool firmly with tape to puncture site Serum preparation: Once collected, serum tubes will be allowed to clot for 30 minutes before centrifugation and plasma tubes immediately spun at 4 degrees for 10 minutes. Once spun, serum or plasma aliquots will be made and stored at -80°C until analysis. RAST Allergy testing The RAST (radioallergosorbent test) serum specific IgE test will be used to identify and assess the presence of allergic sensitisation to grass pollens. As the level of specific IgE increases, the likelihood of clinical relevance also increases. ImmunoCAP Specific IgE assay is used for determination of specific IgE antibodies, and values are expressed in kUA/l, where A represents allergen-specific antibodies. Results above 0.1 kUA/l are indicative of an allergen specific IgE sensitization. ImmunoCAP Allergen GX2, grass pollen test contains a mix of Cynodon dactylon (Bermuda / Couch grass), Lolium perenne (perennial ryegrass), Phleum pratense (Timothy grass), Poa pratensis (Kentucky bluegrass), Sorghum halepense (Johnson grass) and Paspalum notatum (Bahiagrass) (12). Peak Nasal Inspiratory Flow Peak nasal inspiratory flow (PNIF) is a measure of nasal patency and measures the maximum airflow a patient is able to produce during forced nasal inspiration. It has been shown to provide highly reproducible results and correlates with subjective feelings of nasal obstruction. PNIF measures the total nasal flow, therefore it is not dependent on the changing resistances between the left and right nostril. PNIF (in L/min) will be measured with a peak inspiratory flow meter. The highest of three successive measurement values will be recorded (13). Nasal allergen challenge The nasal allergen challenge (NAC) reproduces an allergic rhinitis reaction under standardized and controlled conditions and is a simple, safe and inexpensive technique. An allergen is applied to the nasal mucosa to provoke allergic rhinitis symptoms. Clinical changes will be assessed by symptom scores (VAS) and measuring nasal patency (PNIF). The NAC will be administered by the trial doctor according to standard procedures (14, 15). Plans to promote participant retention and complete follow-up {18b} To promote participant retention and compliance, reminder emails will be sent to participants with the link to the online daily questionnaires. Additional reminders will be sent for study visits. Data management {19} To minimise the risk of participant data security, CRFs contain no details that can be used to directly identify participants. The single exclusion to this is the Adverse Event form, which includes the participant’s name to facilitate identification by medical practitioners. An identification code will be assigned to each participant, which will then be used to identify each participant’s CRF; only the identification code will be recorded on the CRFs. The restricted access Admin Data file (Realtime) will be used to link the participant’s name with the identification code. Hence, CRFs and recorded data will be re-identifiable with details of the respective participant. It is necessary for the data to be re-identifiable by the CRO (only) in order to facilitate Investigators’ contact with participants to (i) proactively conduct compliance activities, and (ii) where necessary, record adverse events and arrange medical assessment. Confidentiality {27} During the trial, data is primarily collected using electronic mediums (secure websites and databases). Any hard copy data collected will stored in participant folders in locked filing cabinets. All electronic data (including master trial documents) is stored on secure servers (e.g., Dropbox Business) on secure computers with access only to trial investigators. Dropbox business servers are located within Australia. Upon completion of the trial, the participant files and trial documents are kept for a period of 15 years. After 15 years, hard copy records will be disposed via certified secure destruction upon conclusion of the retention period and all electronic records removed. Plans for collection, laboratory evaluation and storage of biological specimens for genetic or molecular analysis in this trial/future use {33} Upon collection, blood samples will be centrifuged for 10 minutes at 1800g (3100 RPM) and 4 degrees Celsius, aliquoted and stored at -80°C for later analysis. The samples will be stored in a -80°C freezer in a secured and locked laboratory on site. Statistical methods Statistical methods for primary and secondary outcomes {20a} All analyses will be conducted using Stata (V18), GraphPad Prism (V10) or SPSS (V22). In all statistical tests a significant difference between groups will be considered at a level of p < 0.05 (Bonferroni adjusted for multiple comparisons). Data of subjects that are withdrawn from the study will be included in the statistical analysis on an intention-to-treat basis unless they withdraw after induction but prior to commencing treatment. Primary Outcome Measures : Symptom Severity will be measured using a Visual Analogue Scale (VAS) for nasal congestion, sneezing, itchy nose, runny nose, and watery eyes. These VAS scores will be analyzed as follows: Analysis of primary endpoint : Differences in VAS scores between the investigational product and placebo for each symptom (nasal congestion, sneezing, itchy nose, etc.) will be assessed using a paired t-test or Wilcoxon signed-rank test (depending on normality of data). Timepoint comparison : Symptom severity will also be compared between treatment periods (IP 1 vs. IP 2) using a mixed-effects model for repeated measures, controlling for baseline values and period effects. Secondary Outcome Measures : Statistical testing will use repeated measures analysis (ANOVA or mixed-effects model) to evaluate the effect of treatment over time. Change from baseline will be assessed using paired t-tests or Wilcoxon signed-rank tests. Onset of action will be analyzed descriptively (time to symptom relief after administration of IP or placebo) using Kaplan-Meier survival curves and log-rank tests. Cytokines, histamine, tryptase, and allergen-specific IgE will be analyzed using paired t-tests or non-parametric tests if the data is not normally distributed. Rescue medication use will be compared between groups using descriptive statistics and Chi-square tests to assess frequency differences. Safety Analysis : Safety data will be analysed using descriptive statistics. Adverse events (AEs) will be classified by severity and relationship to treatment. The incident rate ratio (IRR) between treatment arms (placebo vs. IP) will be calculated. Descriptive Statistics: Baseline characteristics will be summarised by intervention group. Discrete variables will be summarized by frequencies and percentages calculated according to the number of trial participants for whom data are available. Where values are missing, the actual denominator will be stated. Continuous variables will be summarized using standard measures of central tendency and dispersion, using either mean ± SD for data with normal distribution, or median and interquartile range for non-normally distributed data. Interim analyses {21b} No interim analysis is planned. Methods for additional analyses (e.g. subgroup analyses) {20b} No subgroup analysis is planned. Methods in analysis to handle protocol non-adherence and any statistical methods to handle missing data {20c} If a participant withdraws from the study, information collected up until the withdrawal point will be used unless the participant requests otherwise. Where values are missing, the actual denominator will be stated. Continuous variables will be summarized using standard measures of central tendency and dispersion, using either mean ± SD for data with normal distribution, or median and interquartile range for non-normally distributed data. Plans to give access to the full protocol, participant level-data and statistical code {31c} After publication of the study results, deidentified data may be obtained from the sponsor upon request. Oversight and monitoring Composition of the coordinating centre and trial steering committee {5d} Not applicable. Composition of the data monitoring committee, its role and reporting structure {21a} Not applicable. Adverse event reporting and harms {22} An Adverse Event (AE) is defined as any untoward and unintended medical occurrence or response to the trial intervention, at any quantity administered, reported by the participant (or noticed by an investigator), which does not necessarily have a causal relationship with the investigational product. Pre-existing diseases or conditions will not be considered as AEs unless there is an increase in the frequency or severity, or a change in the quality of the disease or condition (i.e., it is worsened significantly during the treatment). An AE can therefore be any unfavourable or unintentional clinical signs or symptoms and any new illness or disease or the deterioration of existing disease or illness whether or not related to the investigational product. Frequency and plans for auditing trial conduct {23} Completeness and accuracy of source data recording on case record form will be verified by an investigator upon receipt and then, if required, clarified with the participant. Data manually entered into analysis spread sheets shall be verified by a second investigator (by comparing source data to the inputted data); records including date and initials of the investigators entering and verifying the data will be recorded in the spreadsheet. A data monitoring committee is not needed for this trial due to the nature of the trial and trial population. This trial is not comparing rates of mortality or major morbidity. The trial population is not at an elevated level of risk for death or serious illness. No children, pregnant women, terminally ill or other vulnerable populations are included in the trial. The investigators will permit study-related monitoring, audits, Human Research Ethics Committees review, and regulatory inspection(s) and provide direct access to source data/documents. Plans for communicating important protocol amendments to relevant parties (e.g. trial participants, ethical committees) {25} Any protocol amendment will be pre-approved by the Human Research Ethics Committees. A protocol amendment that affects sample size or outcome assessments will be reported to the trial registry and funder. Dissemination plans {31a} Study results will be presented at scientific conferences, and published in a peer-reviewed journal. Discussion AR constitutes a significant global health burden, having a negative socio-economic impact and limiting quality of life ( 16 ). Pharmacological treatment of AR includes the use of antihistamines, intranasal steroids, leukotriene receptor antagonists, and immunotherapy ( 17 ). Despite these treatment options, many people turn to complementary medicine to manage their allergies, including herbal medicines and nutritional supplements ( 18 ) for which the evidence base of efficacy remains scarce. The immunomodulating activities of yeast β-1,3 − 1,6-glucans were described in both preclinical and clinical studies with beneficial effects on the severity of cold and flu symptoms in various populations ( 19 ). Specifically for allergies, one double-blind, placebo-controlled study evaluated the effects of 12 weeks of 10 mg of glucans taken twice daily in 24 Olea europea sensitised participants. The results showed that Th2 cytokines (interleukin-4 and − 5) and eosinophils in nasal fluid were significantly reduced in the treatment group, while there was a significant increase in Th1 cytokines (interleukin 12) compared to placebo ( 20 ). Of note, AR is an Immunoglobulin E (IgE)-mediated inflammatory reaction driven in part by the overproduction of Thelper (Th)2 cytokines, which results in the stimulation of eosinophils. In another randomized, controlled trial (RCT) comparing the effects of daily supplementation for 4 weeks with 250 mg of a yeast β-1,3 − 1,6-glucan preparation in participants allergic to ragweed, symptoms, overall physical health, and emotional well-being were significantly improved compared with placebo ( 21 ). Taken as a whole, the current evidence base supports the notion that β-glucan supplementation may reduce AR symptom severity, improve quality of life and have a good safety profile ( 22 ). Considering this, the current study was designed to evaluate the efficacy and safety of a 500 mg daily dose of a purified yeast β-glucan preparation (M-Gard®) on the severity of nasal and ocular symptoms in individuals with seasonal AR. Trial status Recruitment began in May 2025 (Protocol Number 202502222 V2.0 27 May 2025). Recruitment completion is anticipated on September 30, 2025. Abbreviations AE Adverse event AR Allergic rhinitis CRF case report form E/LFT Electrolytes/Liver Function Tests FBC Full Blood Count IP Investigational product MCC microcrystalline cellulose NAC nasal allergen challenge OTC over-the-counter PI Principal Investigator PICF participant information and consent form PNIF Peak nasal inspiratory flow RAST radioallergosorbent test RCSS Rhinitis Control Scoring System RQLQ Rhinoconjunctivitis Quality of Life Questionnaire rTNSS Reflective Total Nasal Symptom Scores rTOSS Reflective Total Ocular Symptom Scores SAE serious adverse event VAS Visual Analogue Scale Declarations Acknowledgements We would like to thank Rolf Engstad for participation in the study design. Authors’ contributions {31b} TAT and AR conceived the study. AR led the proposal and protocol development. DB, JP and GB contributed to the study design and to the development of the proposal and protocol. TAT contributed to the study design. JP and GB contributed to the development of the protocol. AT drafted the manuscript. All authors reviewed and approved the final manuscript. Funding {4} This clinical trial is funded by Lallemand Bio-Ingredients. Availability of data and materials {31b} The funder, Lallemand Bio-Ingredients, will have access to the final trial dataset. Ethics approval and consent to participate {24} This trial was approved by the Belberry Human Research and Ethics Committee, Protocol Number 202502222 on 2 nd April 2025. All study activities will be conducted in accordance with the Declaration of Helsinki, and all participants will provide written informed consent. This trial was registered at clinicaltrials.gov (NCT06907680). Consent for publication {32} Not applicable. Competing interests {28} TAT and AT are employed by Lallemand Bio-Ingredients. All other authors declare that they have no competing interests. Authors’ information (optional) Not applicable. References Siddiqui ZA, Walker A, Pirwani MM, Tahiri M, Syed I. Allergic rhinitis: diagnosis and management. Br J Hosp Med (Lond). 2022;83(2):1-9. Australian Bureau of Statistics. National Health Survey: State and territory findings. 2022. ABS. https://www.abs.gov.au/statistics/health/health-conditions-and-risks/national-health-survey-state-and-territory-findings/latest-release. last access: June 20, 2025. van Steenwijk HP, Bast A, de Boer A. Immunomodulating Effects of Fungal Beta-Glucans: From Traditional Use to Medicine. Nutrients. 2021;13(4). Mirończuk-Chodakowska I, Kujawowicz K, Witkowska AM. Beta-Glucans from Fungi: Biological and Health-Promoting Potential in the COVID-19 Pandemic Era. Nutrients. 2021;13(11). Moreno et al. Submitted to the Journal of Dietary Supplements. McLoughlin R, Berthon BS, Rogers GB, Baines KJ, Leong LEX, Gibson PG, et al. Soluble fibre supplementation with and without a probiotic in adults with asthma: A 7-day randomised, double blind, three way cross-over trial. EBioMedicine. 2019;46:473-85. Klimek L, Bergmann KC, Biedermann T, Bousquet J, Hellings P, Jung K, et al. Visual analogue scales (VAS): Measuring instruments for the documentation of symptoms and therapy monitoring in cases of allergic rhinitis in everyday health care: Position Paper of the German Society of Allergology (AeDA) and the German Society of Allergy and Clinical Immunology (DGAKI), ENT Section, in collaboration with the working group on Clinical Immunology, Allergology and Environmental Medicine of the German Society of Otorhinolaryngology, Head and Neck Surgery (DGHNOKHC). Allergo J Int. 2017;26(1):16-24. Sybilski A. Visual analogue scale. A simple tool for daily treatment monitoring in allergic rhinitis. Pediatria i Medycyna Rodzinna. 2018;14:277-81. Downie SR, Andersson M, Rimmer J, Leuppi JD, Xuan W, Akerlund A, et al. Symptoms of persistent allergic rhinitis during a full calendar year in house dust mite-sensitive subjects. Allergy. 2004;59(4):406-14. Boulay M-E, Boulet L-P. The Rhinitis Control Scoring System: Development and Validation. American Journal of Rhinology & Allergy. 2016;30(1):54-9. Juniper EF, Thompson AK, Ferrie PJ, Roberts JN. Validation of the standardized version of the Rhinoconjunctivitis Quality of Life Questionnaire. J Allergy Clin Immunol. 1999;104(2 Pt 1):364-9. ImmunoCAPTM, Phadia, 2019. Available from: https://dfu.phadia.com/Data/Pdf/5dae9e2489c23208b8036206.pdf. Boelke G, Berger U, Bergmann KC, Bindslev-Jensen C, Bousquet J, Gildemeister J, et al. Peak nasal inspiratory flow as outcome for provocation studies in allergen exposure chambers: a GA(2)LEN study. Clin Transl Allergy. 2017;7:33. Augé J, Vent J, Agache I, Airaksinen L, Campo Mozo P, Chaker A, et al. EAACI Position paper on the standardization of nasal allergen challenges. Allergy. 2018;73(8):1597-608. Cho SH, Nanda A, Keswani A, Adinoff A, Baroody FM, Bernstein JA, et al. Nasal allergen challenge (NAC): Practical aspects and applications from an EU/US perspective-a Work Group Report of the AAAAI Rhinitis, Rhinosinusitis and Ocular Allergy Committee. J Allergy Clin Immunol. 2023;151(5):1215-22.e4. Dierick BJH, van der Molen T, Flokstra-de Blok BMJ, Muraro A, Postma MJ, Kocks JWH, et al. Burden and socioeconomics of asthma, allergic rhinitis, atopic dermatitis and food allergy. Expert Rev Pharmacoecon Outcomes Res. 2020;20(5):437-53. Akhouri S, House SA. Allergic Rhinitis. [Updated 2023 Jul 16]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538186/. Asher BF, Seidman MD, Reddy WD, Omole FS. Integrative medical approaches to allergic rhinitis. Curr Opin Otolaryngol Head Neck Surg. 2015;23(3):221-5. Zhong K, Liu Z, Lu Y, Xu X. Effects of yeast β-glucans for the prevention and treatment of upper respiratory tract infection in healthy subjects: a systematic review and meta-analysis. Eur J Nutr. 2021;60(8):4175-87. Kirmaz C, Bayrak P, Yilmaz O, Yuksel H. Effects of glucan treatment on the Th1/Th2 balance in patients with allergic rhinitis: a double-blind placebo-controlled study. Eur Cytokine Netw. 2005;16(2):128-34. Talbott SM, Talbott JA, Talbott TL, Dingler E. β-Glucan supplementation, allergy symptoms, and quality of life in self-described ragweed allergy sufferers. Food Sci Nutr. 2013;1(1):90-101. De Marco Castro E, Calder PC, Roche HM. β-1,3/1,6-Glucans and Immunity: State of the Art and Future Directions. Mol Nutr Food Res. 2021;65(1):e1901071. Table 1 Table 1 is available in the Supplementary Files section. Supplementary Files Table1.docx SpiritchecklistBETALL.doc Cite Share Download PDF Status: Published Journal Publication published 17 Apr, 2026 Read the published version in Trials → Version 1 posted Editorial decision: Minor revision 20 Mar, 2026 Reviewers agreed at journal 16 Dec, 2025 Reviewers invited by journal 06 Oct, 2025 Editor assigned by journal 17 Aug, 2025 First submitted to journal 12 Aug, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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information","content":"\u003cp\u003eNote\u003cstrong\u003e: the numbers in curly brackets in this protocol refer to SPIRIT checklist item numbers.\u003c/strong\u003e The order of the items has been modified to group similar items (see http://www.equator-network.org/reporting-guidelines/spirit-2013-statement-defining-standard-protocol-items-for-clinical-trials/).\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"639\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 34.1158%;\"\u003e\n \u003cp\u003eTitle {1}\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65.8842%;\"\u003e\n \u003cp\u003eEfficacy and safety of a particulate \u0026beta;-glucan preparation in the treatment of seasonal allergic rhinitis (BETALL): a randomized placebo-controlled crossover trial protocol.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 34.1158%;\"\u003e\n \u003cp\u003eTrial registration {2a and 2b}.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65.8842%;\"\u003e\n \u003cp\u003eclinicaltrials.gov\u003c/p\u003e\n \u003cp\u003eNCT06907680\u003c/p\u003e\n \u003cp\u003eBETALL\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 34.1158%;\"\u003e\n \u003cp\u003eProtocol version {3}\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65.8842%;\"\u003e\n \u003cp\u003eProtocol Number 202502222 V2.0 27 May 2025\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 34.1158%;\"\u003e\n \u003cp\u003eFunding {4}\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65.8842%;\"\u003e\n \u003cp\u003eThe funding for this trial was received from Lallemand Bio-Ingredients.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 34.1158%;\"\u003e\n \u003cp\u003eAuthor details {5a}\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65.8842%;\"\u003e\n \u003cp\u003eDavid Briskey\u003csup\u003e1\u003c/sup\u003e, Janice Pellow\u003csup\u003e1\u003c/sup\u003e, Gemma Beatson\u003csup\u003e1\u003c/sup\u003e, Annie Tremblay\u003csup\u003e2\u003c/sup\u003e, Thomas A. Tompkins\u003csup\u003e2\u003c/sup\u003e, Amanda Rao\u003csup\u003e1\u003c/sup\u003e*\u003c/p\u003e\n \u003cp\u003e\u003csup\u003e1\u003c/sup\u003e RDC Clinical, Brisbane, Queensland, Australia\u003c/p\u003e\n \u003cp\u003e\u003csup\u003e2\u003c/sup\u003e Lallemand Bio-Ingredients, Montreal, QC, Canada\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 34.1158%;\"\u003e\n \u003cp\u003eName and contact information for the trial sponsor {5b}\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65.8842%;\"\u003e\n \u003cp\u003eThomas A. Tompkins Ph.D\u003c/p\u003e\n \u003cp\u003eLallemand Bio-Ingredients\u003c/p\u003e\n \u003cp\u003e1620, rue Prefontaine\u003c/p\u003e\n \u003cp\u003eMontreal, Quebec\u003c/p\u003e\n \u003cp\u003eH1W 2N8\u003c/p\u003e\n \u003cp\u003eCanada\u003c/p\u003e\n \u003cp\[email protected]\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 34.1158%;\"\u003e\n \u003cp\u003eRole of sponsor {5c}\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65.8842%;\"\u003e\n \u003cp\u003eAT and TAT, are employees of Lallemand Bio-Ingredients. TAT was involved in the study design presented herein. AT and TAT are not involved in the conduct, management, analysis, or interpretation of the data. \u0026nbsp;The sponsor will be involved in the decision to submit trial results for publication.\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"},{"header":"Introduction","content":"\u003ch2\u003eBackground and rationale {6a}\u003c/h2\u003e\n\u003cp\u003eAllergic rhinitis (AR) is an atopic condition that is the result of a type 1 hypersensitivity reaction occurring in response to aeroallergens such as pollens from trees, grass, and weeds, or mould spores. Characteristic symptoms include rhinorrhea, sneezing, nasal congestion, pruritis of the nose, and ocular symptoms such as increased lachrymation, redness and pruritis (1). \u0026nbsp;AR can be classified as either seasonal (SAR) or perennial (PAR), with around 40% of cases having features of both. According to the 2022 National Health Survey, AR affects around 23.9% of the Australian population (2). \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eBeta-glucans are groups of polysaccharides found in the cell walls of bacteria, fungi, algae and cereals, and are composed of D-glucose monomers linked by specific glycosidic bonds (3). The shape and structure (i.e., branching characteristics), and molecular weight of\u0026nbsp;β-glucans determine their solubility, bioavailability, and biological activity. Beta-1,3-glucans occur in bacteria,\u0026nbsp;β-1,3/1,4-glucans are found in cereals and marine algae, while\u0026nbsp;β-1,3/1,6-glucans occur mainly in yeasts (long D-glucose chains) and macrofungi (shorter D-glucose chains). Beta-glucans supplements offer several health benefits, including immunomodulatory, anticancer and antimicrobial effects\u0026nbsp;(4). \u0026nbsp;M-Gard\u003csup\u003e®\u003c/sup\u003e Particulate EW (hereafter\u0026nbsp;referred to\u0026nbsp;as M-Gard\u003csup\u003e®\u003c/sup\u003e) is a purified bioactive\u0026nbsp;β-1,3/1,6-\u0026nbsp;glucan supplement,\u0026nbsp;isolated from\u0026nbsp;the cell walls of baker’s yeast (\u003cem\u003eSaccharomyces cerevisiae\u003c/em\u003e).\u0026nbsp;Another study evaluated the effects of a daily dose of 500 mg a day of yeast β-glucan dietary supplementation given for 6 weeks on the antibody response to the seasonal influenza vaccine with positive results\u0026nbsp;(5).\u0026nbsp;The primary\u0026nbsp;outcome\u0026nbsp;of the current study\u0026nbsp;will\u0026nbsp;evaluate the efficacy of a 500\u0026nbsp;mg daily dose of M-Gard\u003csup\u003e®\u0026nbsp;\u003c/sup\u003eon reducing the severity of nasal and ocular symptoms in\u0026nbsp;individuals\u0026nbsp;with seasonal\u0026nbsp;AR. Secondary measures include\u0026nbsp;AR\u0026nbsp;control,\u0026nbsp;peak nasal inspiratory flow, quality of life, use of rescue medications, blood markers (cytokines, histamine, tryptase, and allergen-specific IgE) and safety markers (FBC \u0026amp; E/LFT) via blood test and vital signs (blood pressure, heart rate, oxygen saturation, temperature).\u003c/p\u003e\n\u003ch2\u003eObjectives {7}\u003c/h2\u003e\n\u003cp\u003eThe aim of this study is to assess the safety and efficacy of M-Gard\u003csup\u003e®\u003c/sup\u003e supplementation at 500 mg daily at reducing AR symptoms in generally healthy adults upon exposure to grass pollen. It is hypothesised that M-Gard\u003csup\u003e®\u003c/sup\u003e supplementation will be more effective than placebo in decreasing the number of symptoms or their severity in participants with AR.\u003c/p\u003e\n\u003ch2\u003eTrial design {8}\u003c/h2\u003e\n\u003cp\u003eFigure 1A shows the 14-day supplementation period organization and Figure 1B shows the crossover design organization and complete timeline. Briefly, the 6-week, 2-arm, randomized, crossover study comprises 2 supplementation periods separated by a 2-week washout without any supplementation. Yeast mannan and control supplementation will be blinded and allocated in a 1:1 ratio. The primary aim of the study will assess the relief of AR symptoms, with the hypothesis that 500 mg of M-Gard\u003csup\u003e®\u003c/sup\u003e daily for 2 weeks will be superior to the placebo.\u0026nbsp;\u003c/p\u003e"},{"header":"Methods: Participants, interventions and outcomes","content":"\u003ch2\u003eStudy setting {9}\u003c/h2\u003e\n\u003cp\u003eThis trial will be conducted at RDC Clinical, Level 3, 252 St Pauls Terrace, Fortitude Valley, Brisbane, Queensland.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eEligibility criteria {10}\u003c/h2\u003e\n\u003cp\u003eThe study will include generally healthy adults aged 18-65 years with a BMI 18-35kg/m2 and a history of recurrent seasonal allergic rhinitis. Inclusion will also require a positive radioallergosorbent test (RAST) results for grass allergy during screening. Participants must be able to provide informed consent, agree not to change their current diet and/or exercise routine during entire enrolment period and agree to not participate in another clinical trial during the study period.\u003c/p\u003e\n\u003cp\u003ePotential participants will be excluded in case of serious illness (e.g., liver disease, kidney disease, heart disease, mood disorders, neurological disorders such as multiple sclerosis), unstable illness (e.g., diabetes and thyroid gland dysfunction). Other exclusion criteria will include: Current malignancy (excluding Basal Cell Carcinoma) or chemotherapy or radiotherapy treatment for malignancy within the previous 2 years, symptomatic perennial allergic rhinitis, non-allergic rhinitis, chronic respiratory conditions (e.g., asthma, chronic obstructive pulmonary disease), cognitive damage, acute illness experienced in the past 1 month, or any condition which in the opinion of the investigator makes the participant unsuitable for inclusion. Women attempting to conceive, pregnant or lactating will be excluded, as well as active smokers (nicotine or drug abuse), chronic past and/or current alcohol use (\u0026gt;21 alcoholic drinks per week), individuals allergic to any of the ingredients in the active or placebo formula, using medications that would affect the immune and/or the inflammatory response (e.g. immunotherapy, antihistamines (daily use), corticosteroids, mast cell stabilizers, leukotriene modifiers, and decongestants) or taking Coumadin (Warfarin), Heparin, Dalteparin, Enoxaparin or other anticoagulation therapy including low dose aspirin, tricyclic antidepressants, Clonidine and other central acting alpha-2-agonists, currently participating in any other clinical trial or who have participated in any other clinical trial during the past 1 month.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eWho will take informed consent? {26a}\u003c/h2\u003e\n\u003cp\u003ePotential participants will have a phone call meeting arranged with one of the trial coordinators at least 24 hours after receiving the participant information and consent form. During this call, participants will be screened against the inclusion and exclusion criteria and be given a full explanation of the trial and their requirements. Furthermore, participants will be given the opportunity to ask any questions, have information repeated and verified, and welcomed to consult with a family member or friend prior to providing consent. Following screening, potential participants who wish to enrol will be required to sign an electronic consent form to indicate their understanding and willingness to be included in the trial.\u003c/p\u003e\n\u003ch2\u003eAdditional consent provisions for collection and use of participant data and biological specimens {26b}\u003c/h2\u003e\n\u003cp\u003eNot applicable.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eInterventions\u003c/h2\u003e\n\u003ch2\u003eExplanation for the choice of comparators {6b}\u003c/h2\u003e\n\u003cp\u003eMicrocrystalline cellulose (MCC) will be used as the placebo, as in other β-glucan studies because it effectively replicates the physical properties of β-glucans without the biological effects. It is non-digestible and inert; however, it still may be metabolized to a minor extent by the colonic microbiome. We will assess the impact of the MCC on microbiome composition.\u003c/p\u003e\n\u003ch2\u003eIntervention description {11a}\u003cbr\u003e\u0026nbsp;SPIRIT guidance: Interventions for each group with sufficient detail to allow replication, including how and when they will be administered.\u0026nbsp;\u003c/h2\u003e\n\u003cp\u003eThe investigational product will be a purified yeast cell wall fraction obtained from Baker’s yeast (\u003cem\u003eSaccharomyces cerevisiae\u003c/em\u003e), containing β-glucans (≥\u0026nbsp;80%) and few mannoproteins (≤\u0026nbsp;3,5 %) (M-Gard®, Lallemand Bio-Ingredients, Montreal, QC) provided as capsules, each containing 250 mg of M-Gard\u003csup\u003e®\u003c/sup\u003e.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eCriteria for discontinuing or modifying allocated interventions {11b}\u003c/h2\u003e\n\u003cp\u003eDuring the trial, new information about the risks and benefits of the treatment may become known to investigators. If this occurs, participants will be advised as soon as practically possible about this new information so that they can reassess their willingness to be involved in the trial. In addition, an Investigator may discontinue a participant’s participation in the trial without participant consent based on the following criteria:\u003c/p\u003e\n\u003cp\u003e•\u0026nbsp;When there is an onset of a serious adverse event (SAE), and the Principal Investigator (PI) determines that the participant has to discontinue the study.\u003c/p\u003e\n\u003cp\u003e•\u0026nbsp;When significant AR symptoms are observed, and the PI determines that it is difficult for the participant to continue the study.\u003c/p\u003e\n\u003cp\u003e•\u0026nbsp;Protocol violation that in the opinion of the PI affects the data irreparably or continuous protocol violation e.g. failure to complete questionnaires, non-compliance with taking the study product based on the schedule in the protocol, or major changes in living conditions. The PI will then determine whether the participant has compromised reliability in completing the study.\u003c/p\u003e\n\u003cp\u003e•\u0026nbsp;When the participant is found not to be eligible after the start of the study or, due to new circumstances, no longer meets the listed inclusion or exclusion criteria.\u003c/p\u003e\n\u003cp\u003e•\u0026nbsp;When the participant does not comply with the instructions of the PI.\u003c/p\u003e\n\u003cp\u003e•\u0026nbsp;When the PI deems that the study is to be discontinued.\u003c/p\u003e\n\u003cp\u003e•\u0026nbsp;When medical consultant after case file review deems participant unfit to participate.\u003c/p\u003e\n\u003cp\u003e•\u0026nbsp;When participants start taking concomitant medications that may affect the outcome of the study.\u003c/p\u003e\n\u003cp\u003e•\u0026nbsp;The investigational product has unacceptable adverse effects / adverse drug reactions.\u003c/p\u003e\n\u003cp\u003e•\u0026nbsp;Any other reason at the discretion of the principal investigator or sponsor.\u003c/p\u003e\n\u003ch2\u003eStrategies to improve adherence to interventions {11c}\u003c/h2\u003e\n\u003cp\u003eParticipants will be monitored for dosing compliance. At the completion of the trial, each participant will return unused investigational product to the clinic team where capsules will be counted. Compliance will be calculated by determining the number of dosage units taken divided by the number of dosage units expected to have been taken multiplied by 100. In the event of discrepancy between the information recorded and the amount of investigational product returned, use will be based on the product returned unless an explanation for loss of product has been provided. Non-compliance will be defined as \u0026lt;80 and \u0026gt;120% of their dose, as per randomisation schedule.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eRelevant concomitant care permitted or prohibited during the trial {11d}\u003c/h2\u003e\n\u003cp\u003eParticipants will be asked to maintain their usual diet and physical activity patterns throughout the study and allowed to continue any prescription, over-the-counter (OTC), vitamins, minerals and/or herbal medicines that are not considered to affect the study outcomes. No other medications for the treatment of seasonal AR, other than the investigational product, will be permitted for the duration of the study. As the study will be conducted outside of the grass allergy season, it is expected that participants will not have AR symptoms or need rescue medication other than on the days of the nasal allergen challenge (NAC). The trial doctor will be monitoring participants’ symptoms during the NAC and will provide rescue medication as needed.\u003cstrong\u003e\u003cbr\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003ch2\u003eProvisions for post-trial care {30}\u003c/h2\u003e\n\u003cp\u003eNo post-trial care is anticipated. The study will involve generally healthy adult participants, and their participation is deemed to pose minimal risk. In case of an adverse event potentially related to the study, participants will receive follow-up care until recovery.\u003c/p\u003e\n\u003ch2\u003eOutcomes {12}\u003c/h2\u003e\n\u003cp\u003eThe primary outcome is the relief of AR symptoms, including total and individual AR symptom severity measured by a visual analogue scale (VAS) of nasal congestion, sneezing, itchy nose, runny nose and watery eyes. Symptoms will be rated on a scale of 0 to 10 where 0 is \"not troublesome at all\" and 10 is \"very troublesome\". For each symptom, the difference in VAS scores between the M-Gard and placebo groups will be assessed using a paired t-test or Wilcoxon signed-rank test (depending on normality of data). Symptom severity at specific timepoints will also be compared between treatment periods (IP 1 vs. IP 2) using a mixed-effects model for repeated measures, controlling for baseline values and period effects.\u003c/p\u003e\n\u003ch2\u003eParticipant timeline {13}\u003c/h2\u003e\n\u003cp\u003eThe participants timeline and schedule of assessments is presented in Table 1.\u003c/p\u003e\n\u003cp\u003eOnce enrolled in the study, and having been confirmed as having a grass allergy with a positive RAST result, participants will attend an in-clinic session. Height, weight, BMI and vital signs (blood pressure, heart rate, temperature, O\u003csub\u003e2\u003c/sub\u003e saturation) will be measured and a baseline blood sample obtained. The participants will complete the baseline AR symptom severity VAS, rTNSS, rTOSS, RCSS and the RQLQ. \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eOnce the participant has been randomly allocated the first investigational product, they will take 1 capsule twice daily on days 1-11). Participants will be monitored for IP compliance, concomitant medication use, exercise and dietary changes, and adverse events at day 7.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eOn day 12 participants will return to the RDC Clinic for a NAC test. The participants will take 1 capsule of IP twice daily as per usual. At the clinic, the participants will have their vital signs measured. They will be monitored for IP compliance, concomitant medication use, exercise and dietary changes, and adverse events. Participants will have a cannula inserted and a fasted blood sample will be taken to assess for safety markers. \u0026nbsp;They will complete the VAS, rTNSS and rTOSS prior to undergoing the challenge.\u003c/p\u003e\n\u003cp\u003eThe NAC will be performed in the clinic by the trial doctor. Participants will be administered mixed grass allergen via a nasal spray, providing a standardised dose. Peak nasal inspiratory flow (PNIF) will be measured to assess for nasal patency and allergy symptoms will be rated via the VAS, rTNSS and rTOSS. Participants will be monitored by the trial doctor, in the clinic, for the next 2 hours. Adverse events will be monitored, and blood will be collected to test for serum levels of cytokines, histamine, tryptase, and allergen-specific IgE. Participants will be provided with rescue medications as needed, and their use will be recorded. Participants will also complete the RCSS and RQLQ.\u003c/p\u003e\n\u003cp\u003eOn days 13 and 14, participants will continue to take the study product, and allergy symptoms will be monitored remotely, by means of the AR symptom severity VAS, rTNSS, rTOSS, RCSS and RQLQ. Participants will be monitored for IP compliance, concomitant medication use, exercise and dietary changes, and adverse events on day 14.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAfter a 2-week washout period (days 15-28), participants will return to the clinic on day 29 to repeat the baseline testing before starting the alternative product (days 30-40) and repeat the allergen testing (day 41) as per above. Allergy symptoms will be monitored on days 42 and 43. The washout period of 2 weeks is based on the methodology used by a published study testing consecutive interventional products, with 2-week washouts in-between, in a population with asthma (6).\u003c/p\u003e\n\u003ch2\u003eSample size {14}\u003c/h2\u003e\n\u003cp\u003ePower was determined using G*Power (V3.1) using values from previously conducted studies by RDC Clinical and our experience at conducting trials of this nature. To detect a 40% change in VAS, 15 participants per group are required. To allow for dropouts and non-responders, up to 25 participants per group will be recruited.\u003c/p\u003e\n\u003ch2\u003eRecruitment {15}\u003c/h2\u003e\n\u003cp\u003eAfter reviewing the Study Summary Page, interested potential participants will be required to answer a few basic questions to do with the inclusion/exclusion criteria in order to register their interest. Those who register their interest will be provided with an electronic copy of the participant information and consent form (PICF) to read. Potential participants will have a phone call meeting arranged with one of the trial coordinators at least 24 hours after receiving the PICF. During this call, participants will be screened against the inclusion and exclusion criteria and be given a full explanation of the trial and their requirements. Furthermore, participants will be given the opportunity to ask any questions, have information repeated and verified, and welcomed to consult with a family member or friend prior to providing consent. Following screening, potential participants who wish to enrol will be required to sign an electronic consent form to indicate their understanding and willingness to be included in the trial. \u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eAssignment of interventions: allocation\u003c/h2\u003e\n\u003ch2\u003eSequence generation {16a}\u003c/h2\u003e\n\u003cp\u003eRandomisation will be conducted by someone not involved in the conduct of the trial. The randomisation code for the products will be generated by Random Allocation Software.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eConcealment mechanism {16b}\u003c/h2\u003e\n\u003cp\u003eAll investigational product (active and placebo) will be packed in the same type of container and labelled identically except for the product number (based on the randomisation code). The product will be uniquely numbered and as each participant is enrolled, they will be given one of the numbered products. Trial participants will not know the order of what investigational product they will be taking. Unless medically necessary, only upon the completion of all sample analysis (including statistics) will the randomisation code be revealed.\u003c/p\u003e\n\u003ch2\u003eImplementation {16c}\u003c/h2\u003e\n\u003cp\u003eThe Clinical Project manager, who is not associated with the conduct of the study will carry out the randomization by sealed envelope. The study coordinators will enroll the participants and, by opening the sealed envelopes, will assign the participants to their study arm.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eAssignment of interventions: Blinding\u003c/h2\u003e\n\u003ch2\u003eWho will be blinded {17a}\u003c/h2\u003e\n\u003cp\u003eTrial participant, care provider, investigators and outcomes assessors will be blinded to the allocation sequence.\u003c/p\u003e\n\u003ch2\u003e\u003cbr\u003e\u0026nbsp;Procedure for unblinding if needed {17b}\u003c/h2\u003e\n\u003cp\u003eIt is not necessary to unblind a participant’s treatment assignment in most circumstances, even if an SAE has occurred, unless the Principal Investigator (PI) deems unblinding as a necessary step for participant safety. Hence, unless medically necessary, the randomisation codes will be revealed only upon the completion of all sample analysis (including statistics).\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eData collection and management\u003c/h2\u003e\n\u003ch2\u003ePlans for assessment and collection of outcomes {18a}\u003c/h2\u003e\n\u003cp\u003eThe methods for the collection of outcomes are described below: \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eHeight\u003c/u\u003e: measured by stadiometer in metres and without shoes.\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eWeight\u003c/u\u003e: measured by scales in kg and without shoes.\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eBlood pressure\u003c/u\u003e: measured by blood pressure machine in mmHG after sitting for 5 minutes.\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eHeart rate\u003c/u\u003e: measured in BPM by blood pressure machine after sitting for 5 minutes.\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eTemperature\u003c/u\u003e: measured in degrees Celsius by thermometer.\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eO\u003csub\u003e2\u003c/sub\u003e saturation\u003c/u\u003e: measured in % by pulsoximeter.\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eAllergic Rhinitis Symptom Severity Visual Analogue Scale (VAS):\u003c/u\u003e A self-reported tool that measures the severity of the following AR symptoms: nasal congestion, sneezing, nasal itching, runny nose, and watery eyes. These symptoms will be rated on a scale of 0 to 10 where 0 is “not troublesome at all” and 10 is “very troublesome”. Studies have shown that for AR, irrespective of the baseline VAS score, an improvement of 23 mm under therapy indicated effective treatment; an improvement of 30 mm is associated with improvements in QoL parameters. MACVIA ARIA defined AR control cut-offs are: \u0026gt;50: uncontrolled, 20–50: partly controlled, and \u0026lt;20: well controlled. A VAS has been shown to be a reliable and practical means to assess AR symptoms and AR control. Individual symptom severity scores and total allergic rhinitis severity scores will be calculated (7, 8).\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eReflective Total Nasal Symptom Scores (rTNSS):\u003c/u\u003e Self-reported questionnaire rating the severity of four nasal symptoms (runny nose, nasal congestion, itchy nose, and sneezing) on a four-point scale (0-3), where 0 = no symptoms, 1 = mild symptoms, 2 = moderate symptoms, and 3 = severe symptoms. The rTNSS is the sum of the scores for each of the nasal symptoms (from 0 to 12) (9).\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eReflective Total Ocular Symptom Scores (rTOSS):\u003c/u\u003e Self-reported questionnaire that is calculated as the sum of the participants’ scoring of the severity of three ocular symptoms (itching/burning, tearing/watering, and redness) on a scale of 0-3 where 0 = absent, 1 = mild, 2 = moderate, and 3 = severe).\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eRhinitis Control Scoring System (RCSS):\u003c/u\u003e A brief, validated, subject-completed tool including 5 items (sneezing, rhinorrhea, nasal obstruction, nasal pruritus, and conjunctivitis). Each symptom is rated on a 5-point scale depending on its intensity (none-10%, mild-8%, moderate-6%, severe-4%, very severe-2%) and its frequency (never-10%, rarely-8%, occasionally-6%, frequently-4%, very frequently-2%), which are assessed separately. The sum of the intensity score and the frequency score gives the global score (10).\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eRhinoconjunctivitis Quality of Life Questionnaire (RQLQ):\u003c/u\u003e Self-reported questionnaire used measure the functional impairments that are most troublesome to participants because of their rhinoconjunctivitis. It consists of 28 questions in 7 domains (activity limitation, sleep problems, nose symptoms, eye symptoms, non-nose/eye symptoms, practical problems and emotional function). These are rated on a 7-point scale (0 = not impaired at all - 6 = severely impaired). The overall RQLQ score is the mean of all 28 responses and the individual domain scores are the means of the items in those domains (11).\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eBlood markers to be tested:\u003c/u\u003e cytokines, histamine, tryptase, allergen-specific IgE.\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eSafety\u003c/u\u003e will be evaluated via blood test and vital signs (blood pressure, heart rate, O\u003csub\u003e2\u003c/sub\u003e saturation, temperature).\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eBlood sample:\u003c/u\u003e Cannulations and venepunctures will be conducted by a trained phlebotomist.\u003c/p\u003e\n\u003cp\u003eBlood will be collected from an antecubital fossa vein (anterior side of the elbow) using single use needles and vacutainers (for one off draws – Baseline visits) or cannulation (for repetitive draws – NAC visits).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eCannulation and Blood Draw:\u003c/u\u003e\u003c/p\u003e\n\u003cp\u003e-\u0026nbsp;Clean site with an alcohol swab\u003c/p\u003e\n\u003cp\u003e-\u0026nbsp;Insert cannula\u003c/p\u003e\n\u003cp\u003e-\u0026nbsp;Attach one-way valve to cannula\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e-\u0026nbsp;Apply sterile dressing/bandage to hold cannula securely in place\u003c/p\u003e\n\u003cp\u003e-\u0026nbsp;Test patency of cannula by drawing blood into a syringe. If no blood is drawn, the cannula is not in the vein correctly and will need to be repositioned.\u003c/p\u003e\n\u003cp\u003e-\u0026nbsp;Draw 1-2 mL of blood into a waste syringe and dispose\u003c/p\u003e\n\u003cp\u003e-\u0026nbsp;Draw required blood using a fresh syringe\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e-\u0026nbsp;Flush cannula with sterile saline (amount equivalent to total blood drawn)\u003c/p\u003e\n\u003cp\u003eFollowing the completion of the blood draws the cannula and bandages will be removed, and cotton wool applied to the insertion site to stop any bleeding. This wool will remain in place for at least 5 minutes.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ePatency of the cannula will be maintained by flushing the cannula hourly with sterile saline regardless of if there is a blood draw or not.\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eVenepuncture (\u003c/u\u003eFor one of the draws).\u003c/p\u003e\n\u003cp\u003e-\u0026nbsp;Clean site with an alcohol swab\u003c/p\u003e\n\u003cp\u003e-\u0026nbsp;Insert needle with vacutainer holder\u003c/p\u003e\n\u003cp\u003e-\u0026nbsp;Attach each vacutainer and draw a maximum of 10 mL of blood to each container (20 mL total)\u003c/p\u003e\n\u003cp\u003e-\u0026nbsp;Remove needle while applying cotton wool to site\u003c/p\u003e\n\u003cp\u003e-\u0026nbsp;Secure wool firmly with tape to puncture site\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eSerum preparation:\u003c/u\u003e Once collected, serum tubes will be allowed to clot for 30 minutes before centrifugation and plasma tubes immediately spun at 4 degrees for 10 minutes. Once spun, serum or plasma aliquots will be made and stored at -80°C until analysis.\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eRAST Allergy testing\u003c/u\u003e\u003c/p\u003e\n\u003cp\u003eThe RAST (radioallergosorbent test) serum specific IgE test will be used to identify and assess the presence of allergic sensitisation to grass pollens. \u0026nbsp;As the level of specific IgE increases, the likelihood of clinical relevance also increases. ImmunoCAP Specific IgE assay is used for determination of specific IgE antibodies, and values are expressed in kUA/l, where A represents allergen-specific antibodies. Results above 0.1 kUA/l are indicative of an allergen specific IgE sensitization. \u0026nbsp;ImmunoCAP Allergen GX2, grass pollen test contains a mix of Cynodon dactylon (Bermuda / Couch grass), Lolium perenne (perennial ryegrass), Phleum pratense (Timothy grass), Poa pratensis (Kentucky bluegrass), Sorghum halepense (Johnson grass) and Paspalum notatum (Bahiagrass) (12).\u003c/p\u003e\n\u003cp\u003e\u003cu\u003ePeak Nasal Inspiratory Flow\u003c/u\u003e\u003c/p\u003e\n\u003cp\u003ePeak nasal inspiratory flow (PNIF) is a measure of nasal patency and measures the maximum airflow a patient is able to produce during forced nasal inspiration. It has been shown to provide highly reproducible results and correlates with subjective feelings of nasal obstruction. PNIF measures the total nasal flow, therefore it is not dependent on the changing resistances between the left and right nostril. PNIF (in L/min) will be measured with a peak inspiratory flow meter. The highest of three successive measurement values will be recorded (13).\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eNasal allergen challenge\u0026nbsp;\u003c/u\u003e\u003c/p\u003e\n\u003cp\u003eThe nasal allergen challenge (NAC) reproduces an allergic rhinitis reaction under standardized and controlled conditions and is a simple, safe and inexpensive technique. An allergen is applied to the nasal mucosa to provoke allergic rhinitis symptoms. Clinical changes will be assessed by symptom scores (VAS) and measuring nasal patency (PNIF). The NAC will be administered by the trial doctor according to standard procedures (14, 15).\u003c/p\u003e\n\u003ch2\u003ePlans to promote participant retention and complete follow-up {18b}\u003c/h2\u003e\n\u003cp\u003eTo promote participant retention and compliance, reminder emails will be sent to participants with the link to the online daily questionnaires. Additional reminders will be sent for study visits.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eData management {19}\u003c/h2\u003e\n\u003cp\u003eTo minimise the risk of participant data security, CRFs contain no details that can be used to directly identify participants. The single exclusion to this is the Adverse Event form, which includes the participant’s name to facilitate identification by medical practitioners. An identification code will be assigned to each participant, which will then be used to identify each participant’s CRF; only the identification code will be recorded on the CRFs. The restricted access Admin Data file (Realtime) will be used to link the participant’s name with the identification code. Hence, CRFs and recorded data will be re-identifiable with details of the respective participant. It is necessary for the data to be re-identifiable by the CRO (only) in order to facilitate Investigators’ contact with participants to (i) proactively conduct compliance activities, and (ii) where necessary, record adverse events and arrange medical assessment.\u003c/p\u003e\n\u003ch2\u003eConfidentiality {27}\u003c/h2\u003e\n\u003cp\u003eDuring the trial, data is primarily collected using electronic mediums (secure websites and databases). Any hard copy data collected will stored in participant folders in locked filing cabinets. All electronic data (including master trial documents) is stored on secure servers (e.g., Dropbox Business) on secure computers with access only to trial investigators. Dropbox business servers are located within Australia. Upon completion of the trial, the participant files and trial documents are kept for a period of 15 years. After 15 years, hard copy records will be disposed via certified secure destruction upon conclusion of the retention period and all electronic records removed.\u003c/p\u003e\n\u003ch2\u003ePlans for collection, laboratory evaluation and storage of biological specimens for genetic or molecular analysis in this trial/future use {33}\u003c/h2\u003e\n\u003cp\u003eUpon collection, blood samples will be centrifuged for 10 minutes at 1800g (3100 RPM) and 4 degrees Celsius, aliquoted and stored at -80°C for later analysis. The samples will be stored in a -80°C freezer in a secured and locked laboratory on site.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eStatistical methods\u003c/h2\u003e\n\u003ch2\u003eStatistical methods for primary and secondary outcomes {20a}\u003c/h2\u003e\n\u003cp\u003eAll analyses will be conducted using Stata (V18), GraphPad Prism (V10) or SPSS (V22). In all statistical tests a significant difference between groups will be considered at a level of p \u0026lt; 0.05 (Bonferroni adjusted for multiple comparisons). Data of subjects that are withdrawn from the study will be included in the statistical analysis on an intention-to-treat basis unless they withdraw after induction but prior to commencing treatment.\u003c/p\u003e\n\u003cp\u003e\u003cu\u003ePrimary Outcome Measures\u003c/u\u003e:\u003c/p\u003e\n\u003cp\u003eSymptom Severity will be measured using a Visual Analogue Scale (VAS) for nasal congestion, sneezing, itchy nose, runny nose, and watery eyes. These VAS scores will be analyzed as follows:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cem\u003eAnalysis of primary endpoint\u003c/em\u003e: Differences in VAS scores between the investigational product and placebo for each symptom (nasal congestion, sneezing, itchy nose, etc.) will be assessed using a paired t-test or Wilcoxon signed-rank test (depending on normality of data).\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eTimepoint comparison\u003c/em\u003e: Symptom severity will also be compared between treatment periods (IP 1 vs. IP 2) using a mixed-effects model for repeated measures, controlling for baseline values and period effects.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cu\u003eSecondary Outcome Measures\u003c/u\u003e:\u003c/p\u003e\n\u003cp\u003eStatistical testing will use repeated measures analysis (ANOVA or mixed-effects model) to evaluate the effect of treatment over time. Change from baseline will be assessed using paired t-tests or Wilcoxon signed-rank tests. Onset of action will be analyzed descriptively (time to symptom relief after administration of IP or placebo) using Kaplan-Meier survival curves and log-rank tests. Cytokines, histamine, tryptase, and allergen-specific IgE will be analyzed using paired t-tests or non-parametric tests if the data is not normally distributed. Rescue medication use will be compared between groups using descriptive statistics and Chi-square tests to assess frequency differences.\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eSafety Analysis\u003c/u\u003e:\u003c/p\u003e\n\u003cp\u003eSafety data will be analysed using descriptive statistics. Adverse events (AEs) will be classified by severity and relationship to treatment. The incident rate ratio (IRR) between treatment arms (placebo vs. IP) will be calculated.\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eDescriptive Statistics:\u003c/u\u003e\u003c/p\u003e\n\u003cp\u003eBaseline characteristics will be summarised by intervention group. Discrete variables will be summarized by frequencies and percentages calculated according to the number of trial participants for whom data are available. Where values are missing, the actual denominator will be stated. Continuous variables will be summarized using standard measures of central tendency and dispersion, using either mean ± SD for data with normal distribution, or median and interquartile range for non-normally distributed data.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eInterim analyses {21b}\u003c/h2\u003e\n\u003cp\u003eNo interim analysis is planned.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eMethods for additional analyses (e.g. subgroup analyses) {20b}\u003c/h2\u003e\n\u003cp\u003eNo subgroup analysis is planned.\u003c/p\u003e\n\u003ch2\u003eMethods in analysis to handle protocol non-adherence and any statistical methods to handle missing data {20c}\u003c/h2\u003e\n\u003cp\u003eIf a participant withdraws from the study, information collected up until the withdrawal point will be used unless the participant requests otherwise. Where values are missing, the actual denominator will be stated. Continuous variables will be summarized using standard measures of central tendency and dispersion, using either mean ± SD for data with normal distribution, or median and interquartile range for non-normally distributed data.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003ePlans to give access to the full protocol, participant level-data and statistical code {31c}\u003c/h2\u003e\n\u003cp\u003eAfter publication of the study results, deidentified data may be obtained from the sponsor upon request.\u003c/p\u003e\n\u003ch2\u003eOversight and monitoring\u003c/h2\u003e\n\u003ch2\u003eComposition of the coordinating centre and trial steering committee {5d}\u003c/h2\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003ch2\u003eComposition of the data monitoring committee, its role and reporting structure {21a}\u003c/h2\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003ch2\u003eAdverse event reporting and harms {22}\u003c/h2\u003e\n\u003cp\u003eAn Adverse Event (AE) is defined as any untoward and unintended medical occurrence or response to the trial intervention, at any quantity administered, reported by the participant (or noticed by an investigator), which does not necessarily have a causal relationship with the investigational product. Pre-existing diseases or conditions will not be considered as AEs unless there is an increase in the frequency or severity, or a change in the quality of the disease or condition (i.e., it is worsened significantly during the treatment). An AE can therefore be any unfavourable or unintentional clinical signs or symptoms and any new illness or disease or the deterioration of existing disease or illness whether or not related to the investigational product.\u003c/p\u003e\n\u003ch2\u003eFrequency and plans for auditing trial conduct {23}\u003c/h2\u003e\n\u003cp\u003eCompleteness and accuracy of source data recording on case record form will be verified by an investigator upon receipt and then, if required, clarified with the participant.\u003c/p\u003e\n\u003cp\u003eData manually entered into analysis spread sheets shall be verified by a second investigator (by comparing source data to the inputted data); records including date and initials of the investigators entering and verifying the data will be recorded in the spreadsheet.\u003c/p\u003e\n\u003cp\u003eA data monitoring committee is not needed for this trial due to the nature of the trial and trial population. This trial is not comparing rates of mortality or major morbidity. The trial population is not at an elevated level of risk for death or serious illness. No children, pregnant women, terminally ill or other vulnerable populations are included in the trial.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe investigators will permit study-related monitoring, audits, Human Research Ethics Committees review, and regulatory inspection(s) and provide direct access to source data/documents.\u003c/p\u003e\n\u003ch2\u003ePlans for communicating important protocol amendments to relevant parties (e.g. trial participants, ethical committees) {25}\u003c/h2\u003e\n\u003cp\u003eAny protocol amendment will be pre-approved by the Human Research Ethics Committees. A protocol amendment that affects sample size or outcome assessments will be reported to the trial registry and funder. \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eDissemination plans {31a}\u003c/h2\u003e\n\u003cp\u003eStudy results will be presented at scientific conferences, and published in a peer-reviewed journal.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eAR constitutes a significant global health burden, having a negative socio-economic impact and limiting quality of life (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). Pharmacological treatment of AR includes the use of antihistamines, intranasal steroids, leukotriene receptor antagonists, and immunotherapy (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e). Despite these treatment options, many people turn to complementary medicine to manage their allergies, including herbal medicines and nutritional supplements (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e) for which the evidence base of efficacy remains scarce.\u003c/p\u003e\u003cp\u003eThe immunomodulating activities of yeast β-1,3 − 1,6-glucans were described in both preclinical and clinical studies with beneficial effects on the severity of cold and flu symptoms in various populations (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). Specifically for allergies, one double-blind, placebo-controlled study evaluated the effects of 12 weeks of 10 mg of glucans taken twice daily in 24 Olea europea sensitised participants. The results showed that Th2 cytokines (interleukin-4 and − 5) and eosinophils in nasal fluid were significantly reduced in the treatment group, while there was a significant increase in Th1 cytokines (interleukin 12) compared to placebo (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). Of note, AR is an Immunoglobulin E (IgE)-mediated inflammatory reaction driven in part by the overproduction of Thelper (Th)2 cytokines, which results in the stimulation of eosinophils. In another randomized, controlled trial (RCT) comparing the effects of daily supplementation for 4 weeks with 250 mg of a yeast β-1,3 − 1,6-glucan preparation in participants allergic to ragweed, symptoms, overall physical health, and emotional well-being were significantly improved compared with placebo (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e). Taken as a whole, the current evidence base supports the notion that β-glucan supplementation may reduce AR symptom severity, improve quality of life and have a good safety profile (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eConsidering this, the current study was designed to evaluate the efficacy and safety of a 500 mg daily dose of a purified yeast β-glucan preparation (M-Gard®) on the severity of nasal and ocular symptoms in individuals with seasonal AR.\u003c/p\u003e"},{"header":"Trial status","content":"\u003cp\u003eRecruitment began in May 2025 (Protocol Number 202502222 V2.0 27 May 2025). Recruitment completion is anticipated on September 30, 2025.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eAE\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eAdverse event\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eAR\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eAllergic rhinitis\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eCRF\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ecase report form\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eE/LFT\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eElectrolytes/Liver Function Tests\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eFBC\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eFull Blood Count\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eIP\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eInvestigational product\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eMCC\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003emicrocrystalline cellulose\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eNAC\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003enasal allergen challenge\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eOTC\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eover-the-counter\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003ePI\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ePrincipal Investigator\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003ePICF\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eparticipant information and consent form\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003ePNIF\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ePeak nasal inspiratory flow\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eRAST\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eradioallergosorbent test\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eRCSS\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eRhinitis Control Scoring System\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eRQLQ\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eRhinoconjunctivitis Quality of Life Questionnaire\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003erTNSS\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eReflective Total Nasal Symptom Scores\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003erTOSS\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eReflective Total Ocular Symptom Scores\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eSAE\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eserious adverse event\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eVAS\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eVisual Analogue Scale\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAcknowledgements\u003c/h2\u003e\n\u003cp\u003eWe would like to thank Rolf Engstad for participation in the study design.\u003c/p\u003e\n\u003ch2\u003eAuthors\u0026rsquo; contributions {31b}\u003c/h2\u003e\n\u003cp\u003eTAT and AR conceived the study. AR led the proposal and protocol development. DB, JP and GB contributed to the study design and to the development of the proposal and protocol. TAT contributed to the study design. JP and GB contributed to the development of the protocol. AT drafted the manuscript. All authors reviewed and approved the final manuscript.\u003c/p\u003e\n\u003ch2\u003eFunding {4}\u003c/h2\u003e\n\u003cp\u003eThis clinical trial is funded by Lallemand Bio-Ingredients.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eAvailability of data and materials {31b}\u003c/h2\u003e\n\u003cp\u003eThe funder, Lallemand Bio-Ingredients, will have access to the final trial dataset.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eEthics approval and consent to participate {24}\u003c/h2\u003e\n\u003cp\u003eThis trial was approved by the Belberry Human Research and Ethics Committee, Protocol Number 202502222 on 2\u003csup\u003end\u003c/sup\u003e April 2025. All study activities will be conducted in accordance with the Declaration of Helsinki, and all participants will provide written informed consent. This trial was registered at clinicaltrials.gov (NCT06907680).\u003c/p\u003e\n\u003ch2\u003eConsent for publication {32}\u003c/h2\u003e\n\u003cp\u003eNot applicable.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003eCompeting interests {28}\u003c/h2\u003e\n\u003cp\u003eTAT and AT are employed by Lallemand Bio-Ingredients. All other authors declare that they have no competing interests.\u003c/p\u003e\n\u003ch2\u003eAuthors\u0026rsquo; information (optional)\u0026nbsp;\u003c/h2\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eSiddiqui ZA, Walker A, Pirwani MM, Tahiri M, Syed I. Allergic rhinitis: diagnosis and management. Br J Hosp Med (Lond). 2022;83(2):1-9.\u003c/li\u003e\n\u003cli\u003eAustralian Bureau of Statistics. National Health Survey: State and territory findings. 2022. ABS. https://www.abs.gov.au/statistics/health/health-conditions-and-risks/national-health-survey-state-and-territory-findings/latest-release. last access: June 20, 2025.\u003c/li\u003e\n\u003cli\u003evan Steenwijk HP, Bast A, de Boer A. Immunomodulating Effects of Fungal Beta-Glucans: From Traditional Use to Medicine. Nutrients. 2021;13(4).\u003c/li\u003e\n\u003cli\u003eMirończuk-Chodakowska I, Kujawowicz K, Witkowska AM. Beta-Glucans from Fungi: Biological and Health-Promoting Potential in the COVID-19 Pandemic Era. Nutrients. 2021;13(11).\u003c/li\u003e\n\u003cli\u003eMoreno et al. Submitted to the Journal of Dietary Supplements.\u003c/li\u003e\n\u003cli\u003eMcLoughlin R, Berthon BS, Rogers GB, Baines KJ, Leong LEX, Gibson PG, et al. Soluble fibre supplementation with and without a probiotic in adults with asthma: A 7-day randomised, double blind, three way cross-over trial. EBioMedicine. 2019;46:473-85.\u003c/li\u003e\n\u003cli\u003eKlimek L, Bergmann KC, Biedermann T, Bousquet J, Hellings P, Jung K, et al. Visual analogue scales (VAS): Measuring instruments for the documentation of symptoms and therapy monitoring in cases of allergic rhinitis in everyday health care: Position Paper of the German Society of Allergology (AeDA) and the German Society of Allergy and Clinical Immunology (DGAKI), ENT Section, in collaboration with the working group on Clinical Immunology, Allergology and Environmental Medicine of the German Society of Otorhinolaryngology, Head and Neck Surgery (DGHNOKHC). Allergo J Int. 2017;26(1):16-24.\u003c/li\u003e\n\u003cli\u003eSybilski A. Visual analogue scale. A simple tool for daily treatment monitoring in allergic rhinitis. Pediatria i Medycyna Rodzinna. 2018;14:277-81.\u003c/li\u003e\n\u003cli\u003eDownie SR, Andersson M, Rimmer J, Leuppi JD, Xuan W, Akerlund A, et al. Symptoms of persistent allergic rhinitis during a full calendar year in house dust mite-sensitive subjects. Allergy. 2004;59(4):406-14.\u003c/li\u003e\n\u003cli\u003eBoulay M-E, Boulet L-P. The Rhinitis Control Scoring System: Development and Validation. American Journal of Rhinology \u0026amp; Allergy. 2016;30(1):54-9.\u003c/li\u003e\n\u003cli\u003eJuniper EF, Thompson AK, Ferrie PJ, Roberts JN. Validation of the standardized version of the Rhinoconjunctivitis Quality of Life Questionnaire. J Allergy Clin Immunol. 1999;104(2 Pt 1):364-9.\u003c/li\u003e\n\u003cli\u003eImmunoCAPTM, Phadia, 2019. Available from: https://dfu.phadia.com/Data/Pdf/5dae9e2489c23208b8036206.pdf.\u003c/li\u003e\n\u003cli\u003eBoelke G, Berger U, Bergmann KC, Bindslev-Jensen C, Bousquet J, Gildemeister J, et al. Peak nasal inspiratory flow as outcome for provocation studies in allergen exposure chambers: a GA(2)LEN study. Clin Transl Allergy. 2017;7:33.\u003c/li\u003e\n\u003cli\u003eAug\u0026eacute; J, Vent J, Agache I, Airaksinen L, Campo Mozo P, Chaker A, et al. EAACI Position paper on the standardization of nasal allergen challenges. Allergy. 2018;73(8):1597-608.\u003c/li\u003e\n\u003cli\u003eCho SH, Nanda A, Keswani A, Adinoff A, Baroody FM, Bernstein JA, et al. Nasal allergen challenge (NAC): Practical aspects and applications from an EU/US perspective-a Work Group Report of the AAAAI Rhinitis, Rhinosinusitis and Ocular Allergy Committee. J Allergy Clin Immunol. 2023;151(5):1215-22.e4.\u003c/li\u003e\n\u003cli\u003eDierick BJH, van der Molen T, Flokstra-de Blok BMJ, Muraro A, Postma MJ, Kocks JWH, et al. Burden and socioeconomics of asthma, allergic rhinitis, atopic dermatitis and food allergy. Expert Rev Pharmacoecon Outcomes Res. 2020;20(5):437-53.\u003c/li\u003e\n\u003cli\u003eAkhouri S, House SA. Allergic Rhinitis. [Updated 2023 Jul 16]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538186/.\u003c/li\u003e\n\u003cli\u003eAsher BF, Seidman MD, Reddy WD, Omole FS. Integrative medical approaches to allergic rhinitis. Curr Opin Otolaryngol Head Neck Surg. 2015;23(3):221-5.\u003c/li\u003e\n\u003cli\u003eZhong K, Liu Z, Lu Y, Xu X. Effects of yeast \u0026beta;-glucans for the prevention and treatment of upper respiratory tract infection in healthy subjects: a systematic review and meta-analysis. Eur J Nutr. 2021;60(8):4175-87.\u003c/li\u003e\n\u003cli\u003eKirmaz C, Bayrak P, Yilmaz O, Yuksel H. Effects of glucan treatment on the Th1/Th2 balance in patients with allergic rhinitis: a double-blind placebo-controlled study. Eur Cytokine Netw. 2005;16(2):128-34.\u003c/li\u003e\n\u003cli\u003eTalbott SM, Talbott JA, Talbott TL, Dingler E. \u0026beta;-Glucan supplementation, allergy symptoms, and quality of life in self-described ragweed allergy sufferers. Food Sci Nutr. 2013;1(1):90-101.\u003c/li\u003e\n\u003cli\u003eDe Marco Castro E, Calder PC, Roche HM. \u0026beta;-1,3/1,6-Glucans and Immunity: State of the Art and Future Directions. Mol Nutr Food Res. 2021;65(1):e1901071.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Table 1","content":"\u003cp\u003eTable 1 is available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"trials","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"trls","sideBox":"Learn more about [Trials](http://trialsjournal.biomedcentral.com/)","snPcode":"13063","submissionUrl":"https://www.editorialmanager.com/trls","title":"Trials","twitterHandle":"MedicalEvidence","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Postbiotic, yeast β-glucan, allergy, allergic rhinitis, grass pollen, M-Gard®","lastPublishedDoi":"10.21203/rs.3.rs-7047821/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7047821/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003eAllergic rhinitis (AR) has been shown to be a significant global health burden. Despite the existence of pharmacological treatments, mainly antihistamines, nasal corticosteroids, and decongestants, many individuals with seasonal allergies turn to alternative herbal medicines and nutritional supplements for the management of symptoms. The primary objective of the current study is to evaluate the efficacy and safety of a 500 mg daily dose of a yeast β-glucan preparation (M-Gard\u003csup\u003e\u0026reg;\u003c/sup\u003e) on reducing the severity of nasal and ocular symptoms in a population with seasonal AR.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eThis randomized placebo-controlled crossover trial will evaluate the effect of 500 mg of a 14-day M-Gard\u003csup\u003e\u0026reg;\u003c/sup\u003e or placebo (microcrystalline cellulose) supplementation period on the relief of grass pollen-induced AR symptoms in 20 generally healthy adults (18\u0026ndash;65 years) with a history of recurrent seasonal AR. Participants will consume M-Gard\u003csup\u003e\u0026reg;\u003c/sup\u003e or Placebo during 14 days, starting 12 days before the antigen challenge and ending 2 days after. Each supplementation periods will be separated by a 2-week washout period. Allergy symptoms will be assessed at baseline (Day 0) and on Days 12\u0026ndash;14 using a Visual Analogue Scale (VAS) rating AR symptom severity as primary outcome (nasal congestion, sneezing, itchy nose, runny nose and watery eyes) and validated questionnaires as secondary outcomes (Reflective Total Nasal Symptom Scores (rTNSS), Reflective Total Ocular Symptom Scores (rTOSS), Rhinitis Control Scoring System (RCSS), and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ)). In addition, onset of relief, use of rescue medication, and adverse events will be monitored for up to 2 days after the grass allergen challenge. Peak nasal inspiratory flow (PNIF) and pathology markers (cytokines, histamine, tryptase, and allergen-specific IgE) will also be measured. All outcomes will be analyzed as the change from baseline and between-group comparisons will be assessed using appropriate models.\u003c/p\u003e\u003ch2\u003eDiscussion\u003c/h2\u003e\u003cp\u003eThe study hypothesis is that M-Gard\u003csup\u003e\u0026reg;\u003c/sup\u003e supplementation will be more effective than placebo in reducing AR symptoms. This research will strengthen the evidence base supporting the use of M-Gard\u003csup\u003e\u0026reg;\u003c/sup\u003e as a supplement for the management of AR.\u003c/p\u003e\u003ch2\u003eTrial registration\u003c/h2\u003e\u003cp\u003eNCT06907680\u003c/p\u003e","manuscriptTitle":"Efficacy and safety of a particulate yeast β-glucan preparation in the treatment of seasonal allergic rhinitis (BETALL): a randomized placebo-controlled crossover trial protocol","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-17 12:27:39","doi":"10.21203/rs.3.rs-7047821/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Minor revision","date":"2026-03-20T15:02:39+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2025-12-16T10:57:34+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-10-06T10:59:34+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-08-17T09:08:48+00:00","index":"","fulltext":""},{"type":"submitted","content":"Trials","date":"2025-08-12T13:14:21+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"trials","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"trls","sideBox":"Learn more about [Trials](http://trialsjournal.biomedcentral.com/)","snPcode":"13063","submissionUrl":"https://www.editorialmanager.com/trls","title":"Trials","twitterHandle":"MedicalEvidence","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"527a230d-0b5d-4e7e-b789-96f8ae29471b","owner":[],"postedDate":"October 17th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-04-20T16:00:48+00:00","versionOfRecord":{"articleIdentity":"rs-7047821","link":"https://doi.org/10.1186/s13063-026-09702-7","journal":{"identity":"trials","isVorOnly":false,"title":"Trials"},"publishedOn":"2026-04-17 15:57:27","publishedOnDateReadable":"April 17th, 2026"},"versionCreatedAt":"2025-10-17 12:27:39","video":"","vorDoi":"10.1186/s13063-026-09702-7","vorDoiUrl":"https://doi.org/10.1186/s13063-026-09702-7","workflowStages":[]},"version":"v1","identity":"rs-7047821","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7047821","identity":"rs-7047821","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}