Have you every heard of beta glucans? Well if you haven’t, today’s your lucky day. This source of soluble dietary fiber has a rich history of research for its purported benefits.
However, as with many other types of fiber, beta glucans aren’t just one thing. Depending on the source, they have different effects. Therefore, it’s important to discuss the difference between the source and function of this dietary fiber.
Fortunately, a recent review on the topic breaks this down in a simple way, and gives us some excellent infographics to digest this information. Pun intended.
Dietary sources of beta glucans
Sources of beta glucan in the diet come from 2 primary categories: Cereal grains and non-cereal grains. The effects of each category differ due to structural differences. As a result, it’s easier to determine which sources you want to include in your diet based on their function and your needs.
Cereal grain beta glucan structure is mostly consistent between sources. Of the different cereal grains, barley tends to be highest, followed by oats, then wheat and rice. Cereal grain beta glucan tends to generate beneficial effects on metabolism and the gut.
Cereal grains lower cholesterol and decrease absorption of fat through similar mechanisms. As a a result of binding to bile, beta glucan increases bile acid excretion in feces utilizing more cholesterol for bile synthesis. Furthermore, changes in the microbiome from fermentation of this soluble fiber changes bile acid metabolism.
Cereal grain beta glucan also improves blood glucose. It does this by decreasing gastric emptying, suppressing appetite, and improving insulin sensitivity. Part of this effect is due to fermentation into short chain fatty acids by resident bacteria.
The beneficial effects of cereal grain beta glucan on the gut are due to changes in the microbiome. Many beneficial bacteria that reside in our gut feed on these beta glucans. As a result, consuming them increases the presence of Lactobacilli and Bifidobacteria species.
Fungi and yeast are the primary sources of non-cereal beta glucan in the diet. Due to their different structures, fungal sources of beta glucan tend to have more beneficial effects on the immune system.
Interestingly, fungal sources of beta glucan contain various structures with different effects. Based on the data, mushrooms have the most potent immune-modulating effects. But different mushrooms have different effects due to varying structure.
Fungal beta glucans trick our immune system because their structure resembles those of pathogens. They bind to receptors on immune cells and alter our immune response.
Consequently, they promote beneficial effects by decreasing inflammation and killing tumor cells. Binding to these receptors also generates an antimicrobial response, killing pathogens.
These effects decrease allergic responses, decrease infection risk in susceptible individuals, and lower the risk of Cancer.
Including more beta glucans in your diet promotes beneficial effects on metabolism and immune function. But, the source of this soluble fiber will dictate which beneficial effects you see.
If you want to improve your metabolism, include more cereal grain sources. If you are looking for more of a beneficial effect on the immune system, go for mushroom and yeast.
Metabolic dysfunction and immune dysfunction tend to couple together; people who have problems in one tend to have problems with the other. Therefore, consuming more beta glucan in your diet from both sources may provide a synergistic effect in reducing the risk of chronic disease.