A nutraceutical composition containing 0.01-99% by weight polysaccharides enriched from an extract of beans of Glycine max (L.) Merr. Also disclosed are a method of enriching polysaccharides from pulverized beans of Glycine max (L.) Merr.; a polysaccharide having a backbone of α-(1,6)-linked glucose residues, and one or more galactose or mannose residues are bonded to the C-3 or C-4 position of one or more of the glucose residues by a (1,3)- or a (1,4)-linkage; and a method of treating a subject with such polysaccharides to increase blood cell counts.