Beta-glucans – classification and description, medicinal properties, method of application and doctor's reviews

What are beta-glucans?

β-glucans are a group of high-molecular carbohydrates, a type of glucans - polysaccharides of β-D-glucose (a polysaccharide is a molecule consisting of a chain of identical monosaccharides). Such compounds in the natural environment occur in the composition of mushrooms, cereals (oats, barley, etc.), river algae, seaweed, yeast and other bacteria, performing an important physiological role in the life of these organisms. Having a diverse chemical composition, beta-glucans are not fragmented in the stomach and have a complex effect on the human body, helping to strengthen immunity, lower cholesterol levels, reduce the likelihood of developing cardiovascular diseases and provide other positive effects.

What are beta-glucans in mushrooms?

Fungal beta-glucans are polysaccharides contained in the cell wall and, most often, have a β(1,3) backbone with short β(1,6) branches. Structural differences are a feature of components from mushrooms, distinguishing them from raw materials of plant and bacterial origin. It is the presence of beta-glucans that is the main reason why mushrooms find application in cosmetology, medicine and as supporting biologically active food additives.

Mushroom beta-glucans, what's the difference?

β-glucans are a linear backbone of D-glucose monomers linked by β-glycosidic bonds. At the same time, different molecules have differences in structure, branching characteristics and, accordingly, properties. For example, the β-1,3/1,6-glucan laminarin, which is obtained from the algae kelp, differs in composition and molecular shape from the β-1,3/1,6-glucan pleuran, synthesized from glycine (oyster mushroom), and from another fungal β-1,3/β-1,6-glucan lentinan from shiitake.

Most fungal β-1,3-glucans are resistant to gastric juice. They pass unchanged into the small intestine, where they bind to macrophage receptors in the intestinal wall and are then transported to the spleen, lymph nodes, and bone marrow. In macrophages, the high-molecular-weight β-glucans are cleaved into smaller fragments, which then bind to complement type III receptors (CR-3) on immune cells, including granulocytes. Thus, an immune response is stimulated.

Very often, beta-glucans from mushrooms act on the body in combination with protein and other compounds, providing a unique physiological effect. This is why mushroom preparations with beta-glucan have been used in traditional Chinese medicine for hundreds of years and are actively studied by evidence-based science for the treatment of a wide range of diseases.

Which beta-glucans are best?

The specific action of beta-glucans is determined by the structure of their molecule, molecular weight, degree of branching of side structures, solubility in water and other parameters. In terms of activity against the human body, one of the most effective is beta-glucan 1.3/1.6 D, which is contained in mushrooms, yeasts, and bacteria. Mushroom raw materials in this regard are advantageously different from beta-glucan analogues due to the relative ease of cultivation on an industrial scale, harmlessness to the body and the presence of additional benefits due to the presence of additional active substances (for example, the specific substance cordycepin in the cordyceps mushroom).

Beta-glucan release forms

Beta-glucans, as a dietary supplement, are available in the following forms:

• mushroom powder made from dried and crushed natural raw materials;
• extract from natural raw materials, which contains an increased amount of beta-glucans with high bioavailability;
• Synthesized beta-glucans (tablets, capsules, vitamins) mostly lack synergy with other mushroom components.

Composition

Beta-glucans are a large group of polysaccharides that differ in molecular composition and action. The most important of them are listed in Table 1.

Table 1

Types of β-glucans isolated from mushrooms

Scientific studies show a synergistic effect from the joint intake of various β-glucans, the total effect of which is more significant than when using mushroom biologically active supplements separately.

Lentinan

Lentinan is a beta-glucan isolated from the fruiting bodies of the shiitake mushroom in 1970 by a team of researchers led by G. Chihara. This polysaccharide is considered one of the most active components of the mushroom Lentinula Edodes with the following proven and potentially promising medical effects:

• immunostimulating;
• antitumor;
• antioxidant;
• hypolipidemic;
• nutritional support to prevent cognitive decline associated with obesity.

Despite its complex effects on the body, lentinan is primarily considered as a means of enhancing immunity in cancer patients, as an immunomodulator and tumor growth inhibitor. It is promising both in terms of pharmacological action and due to its low toxicity and the availability of raw materials for its production.

Gryfolan

Grifolane is a 1,3-1,6-β-D-glucan isolated from the edible maitake mushroom (Grifola frondosa). This component has antitumor properties, which has been proven in in vivo experiments and in mouse models in the works of Masuda Y. et al. (2013), Mao GH et al. (2015) and other studies. Grifolane can also be considered as an effective supportive agent in the treatment of diabetes (Chen YH et al., 2015).

MD fraction

MD-fraction is a β-glucan from maitake mushrooms, which is able to activate immunity at the cellular level and have an antitumor effect. The substance was discovered in 1985 by Professor Nanba from Kobe Pharmaceutical University. MD-fraction (M - stands for "maitake") has a special molecular structure that is not found in beta-glucans from other mushrooms. It is believed to have strong immune effects, inhibit tumor growth and metastasis, and is a good means for supporting the body and preventing diseases.

Composition of beta-glucans in medicinal mushrooms (table)

Beta-glucans are found in all mushrooms, especially edible ones, and are important elements of their cellular activity. The content can vary from 1 to 60% depending on the form of supply. The proportion of beta-glucans in dried fruit bodies is presented in Table 2.

Table 2

Beta-glucans medicinal properties

Mushrooms to boost immunity

The effect of beta-glucan on the human immune system is complex and not fully understood. Studies show that, entering the intestine, the molecules are absorbed by the mucosa and activate macrophages, providing local immunity and protecting the endothelium from pathogenic microorganisms. At the same time, lymphocytes are also activated through macrophages, which trigger the defense of other organs. In parallel, some of the beta-glucans enter the blood and trigger the mechanism of cytokine synthesis in the liver and other mechanisms of the immune response.

Activation of immunity is one of the reasons why beta-D-glucans have been considered as an active agent for the treatment and prevention of cancer since the 1980s. Dozens of in vitro and in vivo studies have been devoted to this topic. For example, a summary paper published in 2021 by Laiza Steimbach et al. showed that in 16 clinical trials involving 1,650 patients with 9 types of cancer, the use of beta-glucans in combination with radiation or chemotherapy reduced immune depression and helped restore the number of leukocytes. In particular, the works of F. Hong et al. (2003), Chan GC et al. (2009), Vetvicka V. et al. (2021) noted the adjuvant effect of β-glucans, which resulted in the activation of immune effector cells and C3 phagocytes, which contributes to the destruction of tumor cells.

Beta-glucans in autoimmune diseases

Immune system adaptation through beta-glucans has been considered a crucial factor in autoimmune diseases. However, Therkelsen SP et al. (2014 and 2016) showed a modest effect of using a beta-glucan complex obtained from Brazilian agaric in ulcerative colitis, Crohn's disease, and inflammatory bowel disease.

Anti-inflammatory effects of beta-glucans

The anti-inflammatory effect of beta-glucans isolated from Agaricus blazei and other mushrooms is noted in the studies of Smiderle FR et al. (2008), Du B. et al. (2015), Ruthes AC et al. (2013) and in other works. During oral administration of mushroom beta-glucans in animal models, effects similar to nonsteroidal anti-inflammatory drugs and glucocorticoids were recorded. Presumably, such an effect can be triggered by inhibiting the production of pro-inflammatory cytokines or the enzymes nitric oxide synthase and cyclooxygenase-2. The anti-inflammatory function of beta-glucans is also considered an important factor in the prevention and treatment of Parkinson's disease, Alzheimer's disease and other neurodegenerative diseases.

Beta-glucans for acute respiratory viral infections

There are several studies that have examined the effect of fungal β-glucans on the therapy of respiratory tract infections. For example, Majtan J. (2012) showed that the use of mushroom β-glucan pleuran reduces the frequency of symptoms of acute respiratory viral infections in athletes, increases the number and prevents the decrease in the activity of natural killer cells.

In the work of M. Jesenak and co-authors, the effect of pleuran on morbidity in a group of 175 children aged 3 to 7 years was investigated. In a double-blind, placebo-controlled, randomized, multicenter study, it was shown that the use of mushroom beta-glucan reduces the risk of developing SARS by 15 percentage points, compared with children in the control group.

Beta-glucan contraindications

Being a natural raw material, mushroom beta-glucans are non-toxic to the human body, but their use is contraindicated in the following cases:

• individual glucose intolerance;
• individual intolerance to other components of mushrooms (if beta-glucans are consumed in the form of mushroom powder, extract or in another natural form);
• during pregnancy and lactation;
• It is contraindicated to use beta-glucans for children under 1 year of age.

How to take beta glucan

The scheme of taking beta-glucans depends on the form in which the biologically active supplement is produced. In the case of using capsules, tablets or other pharmacological products, the manufacturer's instructions and the doctor's recommendations should be followed. Beta-glucan in products of natural origin is taken according to the following scheme:

• mushroom powder - to increase the bioavailability of beta-glucans, brew 1 teaspoon in 150 ml of boiling water, let it brew for 5 minutes and take 20 minutes before or after meals 2-3 times a day;
• dry extract - take 1 teaspoon of powder half an hour before meals 1-3 times a day, washed down with water.

Beta-glucans reviews from doctors

Numerous studies have shown that mushroom beta-glucans are non-toxic to the human body and can be taken as a supporting biologically active supplement. Experts note the immunostimulating, anti-inflammatory and other positive effects of taking dietary supplements of natural origin in long courses. You can buy beta-glucans as part of natural mushroom preparations of maitake, shiitake, reishi, cordyceps and other mushrooms in our online store with delivery throughout Ukraine. Such products are recommended to be used together due to the pronounced synergistic effect of different mushrooms.