ß-Glucans (beta-glucans) comprise a group of ß-D-glucose polysaccharides naturally occurring in the cell walls of cereals, yeast, bacteria, and fungi, with significantly differing physicochemical properties dependent on source. Typically, ß-glucans form a linear backbone with 1-3 ß-glycosidic bonds but vary with respect to molecular mass, solubility, viscosity, branching structure, and gelation properties, causing diverse physiological effects in animals.