A polysaccharide isolated from the cell walls of bacteria, plants, and fungi with immunostimulant and antineoplastic activities. In a solubilized form, beta-glucan binds to a lectin site within complement receptor 3 (CR3) on leukocytes, priming the receptor to trigger cytotoxic degranulation of leukocytes when leukocyte CR3 binds to complement 3 (iC3b)-coated tumors. Thus, the attachment of beta-glucan to CR3 of circulating leukocytes simulates leukocytes to kill iC3b-coated tumor cells in the same way as they kill iC3b-coated yeast. (NCI04)

A substance found in bacteria, plants, and certain foods, such as baker's yeast, cereal grains, and mushrooms. It is a type of polysaccharide that is made of a string of glucose (sugar) molecules joined together. Beta-glucan may stimulate the immune system and help kill cancer cells. It is being studied in the treatment of cancer. It is a type of biological response modifier.

Glucose polymers consisting of a backbone of beta(1->3)-linked beta-D-glucopyranosyl units with beta(1->6) linked side chains of various lengths. They are a major component of the CELL WALL of organisms and of soluble DIETARY FIBER.