You've certainly heard that fiber is healthy. However, do you realize that there are different types of dietary fiber? There are two basic categories - soluble and insoluble in water. One form of water-soluble fiber is beta-glucan.
Beta-glucan - what is that?
Beta-glucan is a polysaccharide, which is a complex sugar, just like starch (e.g. potato) or recently fashionable hyaluronic acid, which improves the mechanical functions of the joints. Beta-glucan can be found in cereals: in large quantities in oats and barley, but also in wheat and life. Sources of beta-glucan are also mushrooms (Maitake and Reishi varieties) and yeasts.
For this reason, it is worth choosing oat bran and oat flakes for the first or second breakfast. Why? They contain especially a lot of beta-glucan. Oatmeal eaten every day has a lot of health benefits! Here they are:
Many studies show that beta-glucan strengthens immunity. It works by activating immune cells that eliminate foreign bodies (viruses, bacteria, parasites) from the body. 3 grams of beta-glucan a day are enough to achieve this effect. This corresponds to, for example, 2/3 a cup of oat flakes or 1/3 a cup of wheat bran.
Beta-glucan is particularly indicated in people with a weakened immune system after surgery, radiation or chemotherapy. This type of fiber should also be used by older people (who are often malnourished), professional athletes, manual workers and people exposed to X-rays.
We associate "bad" cholesterol (LDL) with deposits in blood vessels, atherosclerosis, and thus with heart disease. Beta-glucan reduces its level by 5 to 7%. 
How is it that beta-glucan reduces "bad" cholesterol? Its action is two-fold. First of all, beta-glucan forms a thin layer on the walls of the intestine, thanks to which cholesterol is less well absorbed. The second mechanism is to increase cholesterol excretion from the body.
Beta-glucan regulates blood glucose (sugar) levels. It is useful for people who are afraid of diabetes and those already sick. How does it happend? Beta-glucan slows the passage, i.e. the movement of food content in the intestines.
Thanks to this, the body does not absorb sugar from food so quickly, which makes the sugar level more stable, there is no large fluctuations in sugar levels after a meal. What does rapid sugar absorption and fluctuations in sugar levels mean in practice? We want to eat faster! We often reach for an easily available, usually unhealthy snack. And if we eat often, we are naturally at risk of being overweight, and in the worst case even obesity.
Yes, beta-glucan works well in this field. First of all, thanks to the stable blood sugar level, the feeling of satiety lasts longer. Secondly, beta-glucan directly affects the feeling of food - extends the action of cholecystokinin, an appetite suppressing hormone.
Beta-glucan also has something to say about the fashionable topic of good bacteria. Well, it causes the growth of beneficial flora in the intestines.  This was shown on the example of porridge, which, if further studies confirm this, beta-glucan will be on the list of prebiotics - food for intestinal bacteria.
Fiber can be found in all fruits and vegetables. In particular, choose whole grains, fruits, vegetables, including legumes and nuts. Unlike many other polysaccharides, the body cannot digest fiber and break it down into its first parts. Therefore, fiber moves along the gastrointestinal tract in unchanged form. What does it give Due to this property, the stool is more and soft, which prevents constipation. Lack of constipation, in turn, means healthy intestines, a lower risk of hemorrhoids, diverticular disease or cancer.
 Harvard School of Public Health „Fiber“ Link do publikacji: hsph.harvard.edu/nutritionsource/carbohydrates/fiber/ Data dostępu: 03.02.2019 r.
 Othman, R. A., Moghadasian, M. H., & Jones, P. J. (2011). „Cholesterol-lowering effects of oat β-glucan. Nutrition Reviews“, 69(6), 299–309 dx.doi.org/10.1111/j.1753-4887.2011.00401.x [03.02.2019]
 El Khoury, D., Cuda, C., Luhovyy, B. L., & Anderson, G. H. (2012). „Beta glucan: health benefits in obesity and metabolic syndrome.“ Journal of Nutrition and Metabolism, 1–28 dx.doi.org/10.1155/2012/851362 [03.02.2019]
 Valeur J, Puaschitz NG, Midtvedt T et. al, "Oatmeal porridge: impact on microflora-associated characteristics in healthy subjects", https://www.ncbi.nlm.nih.gov/pubmed/26511097 [03.02.2019]
 Mayo Clinic Staff. (2015, September 22). „Dietary fiber: Essential for a healthy diet“ https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/fiber/art-20043983?pg=2 [03.02.2019]