The present invention relates to a composition comprising saccharides extracted from blue-green algae biomass, the said saccharides comprising—；from 55% to 60% of rhamnose by weight, —；from 6.5% to 10% of uronic acid by weight, —；from 5% to 15% of sulfate groups by weight, and—；less than 10% of xylose, glucose and galactose or a mixture thereof calculated by weight upon the total of the composition being 100%.
