The invention relates to a polysaccharide-rich composition comprising beta-glucan, chitin and chitosan extracted from the cell wall of Saccharomyces cerevisiae from biomass by-product resulting from a beer production method. The invention also relates to the method for obtaining same and to the uses thereof. Among other biofunctions, the composition has a selective fat binding effect which makes it suitable for use in the prevention and/or treatment of diseases, such as overweight, obesity, hypercholesterolemia, hypertriglyceridemia, hypertension and cardiovascular disorders. The composition can be formulated as an edible, pharmaceufical or veterinary product.
