Supports Normal Immune Cell Activity Plus Maitake Mushrooms NOW Beta-1,3/1,6-D-Glucan (Beta-Glucan) is a bioactive carbohydrate derived from the cell wall of Saccharomyces cerevisiae, commonly known as Bakers’ yeast. Scientific studies have shown that yeast-derived Beta-Glucan can interact with certain immune cells, including those present in the gut-associated lymphoid tissue (GALT). The GALT exists in the intestinal tract and is known to play a critical role in healthy immune system function. NOW Beta-Glucan is blended with Maitake Mushrooms for complementary support.