Glucans are polysaccharides composed of D-glucose units linked primarily by β-1,3, β-1,4, or β-1,6 glycosidic bonds. They occur naturally in the cell walls of cereals (oats, barley), fungi, yeast, and bacteria. Beta-glucans exhibit immunomodulatory, cholesterol-lowering, and prebiotic effects, making them valuable in functional foods and nutraceuticals. Solubility depends on molecular weight and branching; high-molecular-weight beta-glucans form viscous solutions in water. They are stable under typical food processing conditions and contribute to texture and health benefits without altering flavor significantly. Research from peer-reviewed sources confirms their role in reducing postprandial glucose response and supporting gut health.