Trained Immunity: how yeast beta-glucan helps build long-term resilience


Although COVID-19 is no longer at the top of most people’s minds, health and wellness trends indicate that immune health remains a top priority for consumers. However, the focus has shifted from short-term support to strategies and nutrition supplements that provide long-term defence. 

The concept of trained immunity has gained attention as a way to form immune cell memory and protect against pathogenic reinfection. Learn why training the immune system provides additional support and defence and why a one-of-a-kind yeast-derived beta-glucan can be a powerful immunomodulating ingredient for health and wellness product manufacturers.

Understanding immune function

The immune system works via two primary mechanisms — innate and adaptive (also called acquired) immunity. The innate immune system includes physical barriers like the skin, mucous membranes, stomach acid, and bloodborne protection from white blood cells. Innate immunity is present from birth; it is always active and offers an immediate response to stop or slow the spread of many pathogens.

Adaptive immunity provides a second line of defence. It develops throughout life, using “memory” to learn about a specific invader. It enhances the immune response by producing antibodies against the invader. Adaptive immunity comes after exposure, as with an infection, vaccine or allergy shot. Adaptive immunity has a delayed response but is highly specific and sustained for months to years.

The innate and adaptive immune systems are effective but not always perfect. Sometimes, the innate immune system isn’t strong enough. It only recognises certain foreign invaders and treats each the same way.

The adaptive immune system can be slow to work. Vaccines are crucial to its function, but they are ineffective if administered after the onset of infection, and they don’t always work for everyone. Additionally, both parts of the immune system are sensitive to stress, poor sleep quality, ageing, and nutrient shortfalls, which can hinder function. 

Enhancing one’s nutrition status helps support the innate and adaptive immune systems, allowing them to work better. A wide array of macro and micronutrients are crucial to support the development and function of immune cells and processes. The minerals selenium and zinc are key players as they directly help nourish, strengthen, and prime the immune system so it is ready to act when needed.1

What is trained immunity?

Trained immunity refers to the ability of the innate immune system to develop adaptive features, thus providing enhanced, longer-term protection against pathogenic reinfection from a second, unrelated exposure. It’s characterized by long-term epigenetic changes and metabolic reprogramming of immune cells and pathways. Both internal and external stimuli can trigger trained immunity.2,3,4

Trained immunity is a bridge between the innate and adaptive immune systems. It is activated immediately upon exposure to a pathogen, and its actions last between three to 12 months. Innate immune cells return to an inactivated state when the original pathogen is eliminated. Still, the trained innate system can respond faster and more robustly in future encounters with another pathogenic invasion. The trained immune response differs from an acquired immune response because it can be unrelated to the original pathogen.2,3,4

This emerging concept in immunology is supported by a growing body of research that suggests trained immunity plays a vital role in vaccine response and may be an important tool for preventing infectious diseases and protecting against allergens. It also holds hope as a potential therapeutic strategy to manage certain health conditions associated with immune system malfunction, such as cancer.2

Beta-glucan and trained immunity

It’s possible to induce trained immunity with various external stimuli. One that has been shown to be highly effective is beta-glucan, specifically β-1,3/1,6-glucan, derived from the cell wall of Saccharomyces cerevisiae, also known as baker’s yeast.5 Beta-glucans are derived from various sources, including oats, barley, yeast, mushrooms, and bacteria, but each source affords different health benefits. For example, beta-glucan from oats and barley provides metabolic benefits by reducing lipids and insulin resistance. 

Yeast beta-glucan acts as an immunomodulator, helping the immune system work more effectively by inducing trained immunity and modulating immune cells’ inflammatory and antimicrobial activity. Studies have shown that yeast-derived beta-glucan (β‐1,3/1,6‐glucan) can: 6,7,8,9

  • Strengthen the immune system, offering extra protection during periods of physical or emotional stress
  • Enhance immune system response to vaccination
  • Enhance the protection against allergies 
  • Promote healthy inflammatory responses
  • Support respiratory health 

The ABB C1® beta-glucan complex difference

ABB C1® beta-glucan is a patent-pending, novel, high-complexity blend of two separate beta-glucans (β-1,3/1,6-glucan) from Saccharomyces cerevisiae. Studies show this unique complex can simultaneously activate multiple immune receptors, induce trained immunity, and limit pro-inflammatory mediators released in the innate immune response. 

The ABB C1® beta-glucan complex acts synergistically to yield a more robust trained innate immune response than other yeast-derived beta-glucans. 

ABB C1® beta-glucan complex also provides two other powerful supporting ingredients:

  • Selenium-rich postbiotic from S. cerevisiae. This is unique from other selenium ingredients because selenium is organically bound during a fermentation process and incorporated into the selenoproteins, allowing for high bioavailability with a low risk of toxicity.10,11
  • Zinc-rich postbiotic from S. cerevisiae. The zinc-rich postbiotic is covalently bound during manufacturing and has been shown to have superior absorption and retention over other salt forms of zinc. Additionally, a positive interaction between elemental zinc and its yeast carrier limits zinc’s reaction with other substances in the gut, reducing the chance of toxicity.12

Unlike other yeast-derived beta-glucan bioactives, ABB C1® provides three unique mechanisms of action that work synergistically to have a far more profound impact on the immune system.

  • The novel combination of two highly effective β-1,3/1,6-glucans from S. cerevisiae activates the innate immune system and stimulates trained immunity more effectively than competitors.
  • Selenium and zinc-rich postbiotics provide targeted nutrition to support critical immune cells and antibodies. Combined, these minerals have been shown to be more effective against respiratory infections.13 And most importantly, selenium plus beta-glucan improves the immune modulatory effects of beta-glucan.14
  • S. cerevisiae provides additional immune-modulating effects through its impact on the gut microbiome. It helps bind and neutralize pathogenic microbes, strengthens the gut lining, and promotes a healthy inflammatory response.15,16

Backed by research

A one-month clinical study on 72 subjects showed ABB C1® enhanced the immune system’s response to both the flu and COVID-19 vaccinations compared to placebo. After a single dose, these results showed responses from T-lymphocyte, IgM, and IgG antibodies. Additionally, the product enhanced the immune system response with the second dose of COVID-19, indicating ABB C1TM stimulated trained immunity.17

In that same study, ABB C1® also increased blood concentrations of the vital immune minerals zinc and selenium compared to those taking the placebo.17

In lab studies on intestinal cells and mice immune systems, ABB C1® significantly reduced levels of two primary inflammatory compounds compared to controls. The product also showed significant abilities to protect the gut lining from disruption caused by Escherichia coli, and it improved the gut lining integrity over 22 days compared to the negative control.18

In that same study, ABB C1® showed the highest phagocytosis activity (the ability to engulf and eliminate pathogenic cells) compared to algal beta-1,3-glucan and yeast beta-1,3/1,6-glucan.18

Applying beta-glucans in the market

There is great interest in applying beta‐glucans in the pharmaceutical, food and beverage sectors worldwide. Industry data by Markets and Markets predicts the global beta‐glucan market to be worth USD 501 million in 2023 and USD 734 million by 2028.19

ABB C1® has a wide range of applications in supplements, foods, and beverages for immune and allergy support for manufacturers who wish to capitalise on next-generation products for immune health. 

ABB C1® is available as: 

  • Bulk powder
  • Sticks 
  • Tablets 
  • Capsules 
  • Gummies

  Anne Danahy, MS RDN, is a U.S.-based registered dietitian
  and health writer specialising in nutrition, healthcare, and food. 




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3. Netea, M. G., Quintin, J. & van der Meer, J. W. Trained immunity: a memory for innate host defense. Cell Host Microbe 9, 355–361 (2011).
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Krysten Fries-Craft and others, Dietary Yeast Beta 1,3/1,6 Glucan Supplemented to Adult Labrador Retrievers Alters Peripheral Blood Immune Cell Responses to Vaccination Challenge Without Affecting Protective Immunity. Journal of Animal Science, Volume 101, 2023, skad029, https://doi. org/10.1093/jas/skad029.
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8. Stier H, Ebbeskotte V, Gruenwald J. Immune-Modulatory Effects of Dietary Yeast Beta-1,3/1,6-D-glucan. Nutr J. 2014 Apr 28;13:38. Doi: 10.1186/1475-2891-13-38.
9. Fuller R, Moore MV, Lewith G, Stuart BL, Ormiston RV, Fisk HL, Noakes PS, Calder PC. (2017) Yeast-Derived Beta 1,3/1,6 Glucan, Upper Respiratory Tract Infection and Innate Immunity in Older Adults. Nutrition 39-40:30-35. 
Kim, Y. Y. & Mahan, D. C. Comparative Effects of High Dietary Levels of Organic and Inorganic Selenium on Selenium Toxicity of Growing-Finishing Pigs. J. Anim. Sci. (2001). doi:10.2527/2001.794942x.
11. Payne, R. L. & Southern, L. L. Comparison of Inorganic and Organic Selenium Sources For Broilers. Poult. Sci. (2005). doi:10.1093/ps/84.6.898.
12. Gharekhani A, Azari Takami G, Tukmechi A, Afsharnasab M, Agh N. Effect of Dietary Supplementation With Zinc Enriched Yeast (Saccharomyces Cerevisiae) on the Immunity of Rainbow Trout (Oncorhynchus Mykiss). Iran J Vet Res. 2015 Summer;16(3):278-82.
13. Girodon, F. et al. Impact of Trace Elements and Vitamin Supplementation on Immunity and Infections in Institutionalized Elderly Patients: A Randomized Controlled Trial. Intern. Med. (1999). doi:10.1001/archinte.159.7.748.
14. Vetvicka, V. & Vetvickova, J. Addition of Selenium Improves Immunomodulative Effects of Glucan. Am. J. Med. Sci. 8,88-92(2016).
15. McFarland LV. Systematic Review and Meta-Analysis of Saccharomyces Boulardii in Adult Patients. World J Gastroenterol. 2010;16(18):2202-2222. doi:10.3748/wjg.v16.i18.2202.
16. Palma, M. L. et al. Probiotic Saccharomyces cerevisiae strains as biotherapeutic tools: is there room for improvement? Applied Microbiology and Biotechnology (2015).
17. Rodriguez JAM, Bifano M, Roca Goma E, Plasencia CM, Torralba AO, Font MS, Millán PR. Effect and Tolerability of a Nutritional Supplement Based on a Synergistic Combination of β-Glucans and Selenium- and Zinc-Enriched Saccharomyces cerevisiae (ABB C1®) in Volunteers Receiving the Influenza or the COVID-19 Vaccine: A Randomized, Double-Blind, Placebo-Controlled Study. 2021; 13(12):4347.
18. Tintoré M, Cuñé J, Vetvicka V, de Lecea C. Anti-Inflammatory Effects, Protection of Gut Barrier Integrity and Stimulation of Phagocytosis of Postbiotic Combination ABB C1. 2023; 3(1):109-118.
19. Beta-Glucan Market by Source (Cereal, Mushroom, Yeast, and Seaweed) Application (Food & Beverage, Personal Care, Pharmaceutical, Dietary Supplement, Animal Feed) and Region (North America, Europe, APAC, Latin America, and RoW) – Global Forecast to 2028. Markets and Markets. Published April 2023. Accessed December 5, 2023.

Learn More about ABB C1®

Download our white paper or visit our Immune Health page to learn more about ABB C1®, its immune-modulating actions, and its effects on trained immunity.