SOURCES OF Beta-Glucan

In literature, we can often find contradictory representations on which type of Beta-Glucan is the best. In general, Western civilizations have historically an excess of yeasts thanks to their traditions of bread baking and brewing, and therefore glucan is isolated from baker's yeast Sacharomyces cerevisie (also called ale yeast). On the other hand, the Far East has a long tradition of picking all kinds of mushrooms that have been considered part of folk medicine for millennia. Not surprisingly, China and Japan therefore isolate glucans mostly from mushrooms.

Immunomodulating polysaccharides, and especially glucan, are today the focus of very intensive pre-clinical and clinical trials conducted worldwide. Although the question of which glucan is the best has not been yet answered satisfactorily, we can already draw some conclusions. Glucans isolated from yeast have several huge benefits compared to other glucans - they are cheaper, their source is better definable and their biological activity is greater.

After decades of intensive research, two commercial products from mushroom glucans were approved in Japan in mid-1980s for the treatment of some tumours, particularly tumours of the gastrointestinal tract. Typically, glucans isolated from the edible mushrooms Lentinus edodes (lentinan) and Shizophyllum commune (schizophyllan) are used in Japan, where mushrooms have had a huge importance in fold medicine for centuries.

Western science used another readily available source for research – yeast. While available literature describes glucans isolated from almost all types of yeast, glucans isolated from common yeast Sacharomyces cerevisiae (baker's or ale yeast) have been studied the most and have been demonstrated to have the best biological properties. Glucans, more specifically poly-glucopyranoses, differ from each other in terms of molecular weight and chaining level as well as 3D structure. The immunostimulating activity is associated with a triple-helix conformance of the basic chain; the addition of other side beta-1,6-glycoside chains enhances biological effects even more. Many studies have demonstrated, however, that even though these physical and chemical properties influence the biological activity of glucans, their purity is of a much higher importance.