Less fatigue, a better immune system yet training hard - thanks to beta-glucans
If you have to cope with severe physical stress - for example, because you train hard - supplementation with beta glucans may at the same time reduce fatigue and keep your immune system strong. An animal study that recently appeared in the Open Biochemistry Journal suggests this.Study
The researchers experimented with mice. They forced the animals to swim every day, consecutive days, and caused considerable physical stress in this way. This kind of continuous heavy physical stress causes fatigue and reduces the functioning of the immune system.

The researchers gave the mice in the control group no active substances. [PBS] Other test animals received 50, 100 or 200 micrograms beta-glucans daily. The human equivalent of those doses was approximately 16, 32 and 64 milligrams per day, respectively.
The researchers used Glucan 300 from the American Transfer Point. [transferpoint.com] This is made from yeast.Beta-glucans are also present in plant-based foods such as oatmeal and in edible mushrooms. The precise chemical structure of beta-glucans is different in every food, and probably also their immunological effect.
Less fatigue
After the mice had been swimming for 15 days every day, the researchers gave the animals nothing every day for another 15 days, or a supplement with beta-glucans.

Already on the first day of supplementation [day 0 in the figure below] the researchers saw that the time the mice were floating around passively was shorter when they were given beta glucans. The higher the dose, the stronger the effect.

Beta-glucans apparently reduced fatigue. The effect was sustained after the researchers stopped supplementation.
The researchers saw in the brains of the mice how beta-glucans reduce fatigue: by increasing the concentration of the endogenous antioxidants glutathione [GSH] and superoxide dismutase [SOD].

Immune system
At the same time, beta-glucans improved the functioning of the immune system. The researchers extracted neutrophils from the mice's blood and put them in test tubes with pathogens.

Neutrophils literally eat germs such as fungi and bacteria. This is called phagocytosis. The researchers discovered that beta-glucans, so to speak, fueled the appetite of neutrophils.

The glucans also stimulated the release of interleukin-2 and interleukin-4. Interleukin-4 causes the immune system to attach molecular labels to cells that are to be attacked by the immune system. Interleukin-2 stimulates the development of immune cells that do the actual work and clean up the faulty cells.Mechanism
In the body, beta-glucans activate the complement receptor 3 - present in neutrophils, Natural Killer Cells and macrophages, among others. Beta-glucans also activate the Dectin-1 receptor in macrophages, neutrophils, eosinophils, B cells and dendritic cells.

Through these receptors, beta-glucans boost large parts of the immune system, the researchers suspect. Beta-glucans make immune cells more aggressive, and increase the production of antibodies.
Intensive exercise can be at the expense of the immune system, but supplementation with beta-glucans may partially counteract this effect, the researchers speculate. As a result, pathogens have less chance.
When the fight of the immune system against pathogens starts in full force, aggressive cytokines such as TNF-alpha are released. A high level of that protein goes together with fatigue. By stimulating the immune system and preventing pathogens from gaining a foothold, beta glucans reduce the need to make a lot of TNF-alpha, the researchers suspect.
The Open Biochemistry Journal, 2020, Volume 14.