Abstract

β-Glucans are well-established and powerful immunomodulators. Their history, however, has been complicated and is full of dead ends. Starting from their chemical composition and structure, continuing with their biological effects and activities, and ending with the mechanism of their function, β-glucans are extensively studied for over 70 years. This Chapter is focused on the history of β-glucans, going back to the half of the 19th century, when β-glucan was believed to be a type of cellulose, and to the 40s of the last century when Shear and Turner described a polysaccharide substance, isolated from Serratia marcescens, that caused necrosis of tumors.