A method for lowering serum cholesterol levels, healing a wound, modulating glycaemic response, alleviating constipation, or stimulating the immune system. The method includes administering to a subject in need .beta.-glucan obtained by forming flour from the cereal grain; mixing the flour with water at a temperature in the range of 25-65.degree. C. to form a slurry of an aqueous solution of .beta.-glucan and a solid residue; separating the aqueous solution from the solid residue; removing water from the aqueous solution by evaporating or ultrafiltration or combinations thereof to give a concentrated aqueous solution of .beta.-glucan; and forming a .beta.-glucan gel from the concentrated aqueous solution of .beta.-glucan.