Kate Street

A key ingredient with growing research in this area is Wellmune®, a proprietary β-1,3/1,6-glucan derived from the cell wall of a specific strain of Saccharomyces cerevisiae (baker's yeast).3 While Wellmune first gained attention for its ability to support respiratory immune health, more recent research suggests its benefits may be explained by its ability to promote a phenomenon known as ‘trained innate immunity’.4 <h2>What is Wellmune®?</h2>Wellmune® has been clinically researched across a range of populations, including healthy adults,5,6 older adults,7 and athletes.8 Clinical studies suggest benefits for respiratory health,5,7,8 exercise recovery,4,8 and immune resilience.6 While β-glucans occur naturally in a variety of sources, including cereals, mushrooms, and yeasts, not all β-glucans exert the same biological effects.4 Research suggests that Wellmune interacts with the innate immune system in ways that support immune surveillance and responsiveness, which may help to explain its observed clinical benefits.4  
<table><tbody><tr><td class="bg-gray-100"><h2 class="bg-gray-100">Is Wellmune a postbiotic?</h2>Interest in postbiotics has grown in recent years as research has revealed that preparations of non-living microorganisms, or their components, can confer health benefits.9 Unlike probiotics, which rely on live microorganisms,9 Wellmune is a purified yeast-derived β-glucan.3 Its microbial origin and non-living nature have led to its positioning within the emerging postbiotic category.10 However, whether purified microbial components meet the consensus definition of a postbiotic is still debated.9 </td></tr></tbody></table> <h2>How does Wellmune work?</h2>For many years, the innate immune system was thought to lack memory.11 However, advancements in research over the past decade have challenged this view, demonstrating that innate immune cells can undergo functional reprogramming following exposure to certain microbial compounds or other immunological stimuli.11 This process, known as ‘trained immunity’, enables innate immune cells to respond more efficiently to future challenges.11 Wellmune is among the most extensively studied yeast β-glucans investigated for their potential role in trained immunity.4 As β-glucans are recognised as ‘non-self’ structures, they interact with pattern recognition receptors on innate immune cells, including macrophages and monocytes.3 In laboratory studies, this interaction can trigger cellular, metabolic, and epigenetic adaptations associated with trained immunity, enhancing immune surveillance and responsiveness.11 However, human research in this area is still emerging.3  Preliminary evidence suggests Wellmune® may influence gene expression pathways involved in pathogen recognition, immune signalling, and innate immune function. These molecular changes provide a potential mechanistic explanation for the clinical benefits observed with supplementation.4 
<h2>Key clinical research findings</h2>Much of the early clinical research on Wellmune focused on respiratory health outcomes, with studies demonstrating reductions in upper respiratory tract infection (URTI) symptoms, symptom severity, and illness-related disruptions to daily life.5 However, rather than viewing these findings in isolation, researchers increasingly consider them potential downstream effects of enhanced innate immune readiness.4 This shift in thinking has prompted a growing focus on understanding the molecular mechanisms underlying Wellmune's effects.4 Table 1. Clinical evidence demonstrating the immune benefits of Wellmune<table><tbody><tr><td>Population </td><td>Wellmune dose </td><td>Duration </td><td>Key findings </td></tr><tr><td>Healthy adults </td><td>500 mg/day </td><td>12 weeks </td><td>Improved quality of life and fewer days missed from work or school due to URTIs.5 </td></tr><tr><td>Healthy adults </td><td>50-250 mg/day (escalating dose) </td><td>6 weeks </td><td>Changes in 40 immune-related markers associated with trained innate immunity, pathogen recognition, and inflammatory responses.6 </td></tr><tr><td>Marathon runners </td><td>250 mg/day </td><td>45 days before and after event </td><td>Fewer upper respiratory symptom days and reduced symptom severity following marathon participation.8 </td></tr><tr><td>Older adults (50–70 years) </td><td>250 mg/day </td><td>90 days </td><td>Fewer reported URTIs and reduced number of symptom days.7 </td></tr><tr><td>Physically active adults </td><td>50-250 mg/day (escalating dose) </td><td>6 weeks </td><td>Changes in 47 immune-related markers associated with immune function, pathogen recognition, and recovery following exercise.4 </td></tr></tbody></table> <table><tbody><tr><td class="bg-gray-100"><h2>Research spotlight: supporting immune resilience after exercise </h2>For athletes and physically active individuals, intense exercise can temporarily challenge immune function. This transient disruption has been associated with an increased risk of upper respiratory symptoms during recovery, making immune resilience an important consideration for training, performance, and recovery.3 A 2024 study investigated the effects of six weeks of Wellmune supplementation at an escalating dose (50 mg/day for the first two weeks, 125 mg/day for the next two weeks, and 250 mg/day for the last two weeks) in physically active adults undertaking a 90-minute whole-body exercise challenge.4 Researchers identified changes in 47 genes involved in innate immune function, pathogen recognition, and inflammatory signalling.4 The findings suggest Wellmune® may enhance the innate immune system's ability to respond to physiological stress and support recovery following strenuous exercise.4 Interestingly, a subsequent 2025 study reported changes in gene expression consistent with trained innate immunity following six weeks of Wellmune supplementation at the same escalating dose (50 mg/day for the first two weeks, 125 mg/day for the next two weeks, and 250 mg/day for the last two weeks), even in the absence of an exercise challenge.6 Together, these findings suggest Wellmune® may influence innate immune function under both stressed and resting conditions, providing further insight into the mechanisms that may underpin its effects on immune resilience.6 </td></tr></tbody></table><h2>Conclusion</h2>While Wellmune first gained attention for its respiratory health benefits, growing evidence suggests a broader role in supporting innate immune function and immune resilience. As understanding of trained immunity advances, Wellmune remains one of the most extensively researched yeast β-glucans for supporting the body's first line of defence, and larger studies will help to further clarify its benefits. References 1 Chen JY, Shih LJ, Liao MT, Tsai KW, Lu KC, Hu WC. Understanding the immune system’s intricate balance: Activation, tolerance, and self-protection. Int J Mol Sci. 2025;26(12):5503. doi:10.3390/ijms26125503 2 Munteanu C, Schwartz B. The relationship between nutrition and the immune system. Front Nutr. 2022;9:1082500. doi:10.3389/fnut.2022.1082500 3 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. doi:10.1002/mnfr.201901071 4 McFarlin BK, Bridgeman EA, Curtis JH, Vingren JL, Hill DW. Baker’s yeast beta glucan supplementation was associated with an improved innate immune mRNA expression response after exercise. Methods. 2024;230:68–79. doi:10.1016/j.ymeth.2024.07.013 5 Feldman S, Schwartz H, Kalman D, et al. Randomized phase II clinical trials of Wellmune WGP for immune support during cold and flu season. The Journal of Applied Research. 2009;9. 6 McFarlin BK, Curtis JH, Vingren JL, Hill DW, Bridgeman EA. Discovery of innate immune response mRNAs that are impacted by structure-specific oral baker’s yeast beta glucan consumption. BioTech (Basel). 2025;14(1):4. doi:10.3390/biotech14010004 7 Fuller R, Moore MV, Lewith G, Stuart BL, Ormiston RV, Fisk HL, et al. Yeast-derived β-1,3/1,6 glucan, upper respiratory tract infection and innate immunity in older adults. Nutrition. 2017;39–40:30–5. doi:10.1016/j.nut.2017.03.003 8 Mah E, Kaden VN, Kelley KM, Liska DJ. Soluble and insoluble yeast β-glucan differentially affect upper respiratory tract infection in marathon runners: A double-blind, randomized placebo-controlled trial. J Med Food. 2020;23(4):416–9. doi:10.1089/jmf.2019.0076 9 Meena KK, Joshi M, Gupta L, Meena S. Comprehensive insights into postbiotics: Bridging the gap to real-world application. Food Nutrition. 2025;1(2):100024. doi:10.1016/j.fnutr.2025.100024 10 Wellmune. 2024 [cited 2026 Oct 8]. What is wellmune? Available from: https://wellmune.com/what-is-wellmune/ 11 Netea MG, Domínguez-Andrés J, Barreiro LB, Chavakis T, Divangahi M, Fuchs E, et al. Defining trained immunity and its role in health and disease. Nat Rev Immunol. 2020;20(6):375–88. doi:10.1038/s41577-020-0285-6

<h3>Key highlights </h3><ul><li>Wellmune® is a yeast-derived β-glucan from Saccharomyces cerevisiae.</li><li>Clinical studies suggest Wellmune supports respiratory health, exercise recovery, and immune resilience.</li><li>A growing body of research suggests Wellmune supports trained immunity, helping prepare innate immune cells to respond more effectively to future challenges. </li><li>Recent mechanistic studies suggest Wellmune influences gene expression pathways involved in innate immune function.</li></ul>

Key highlights

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