Prebiotics are non-digestible, selectively fermented compounds that stimulate the growth and/or activity of beneficial gut microbiota which, in turn, confer health benefits on the host. Fucoidan, laminarin, alginate and their derivatives, may offer potential for use as prebiotics. Others are Phaeophyta, or brown seaweeds, are predominantly brown due to the presence of the carotenoid fucoxanthin and the primary polysaccharides present include alginates, laminarins, fucans and cellulose . Chlorophyta, or green seaweeds, are dominated by chlorophyll a and b, with ulvan being the major polysaccharide component. The principal pigments found in rhodophyta, or red seaweeds, are phycoerythrin and phycocyanin and the primary polysaccharides are agars and carrageenans.