The structure of the extracellular polysaccharide (EPS) from Lactobacillus rhamnosus strain GG has been investigated. In combination with component analysis, NMR spectroscopy shows that the polysaccharide is composed of hexasaccharide repeating units. Sequential information was obtained by two-dimensional NOESY. and H-1, C-13-HMBC NMR techniques. The structure of the repeating unit of the EPS from Lactobacillus rhamnosus strain GG was determined as: [GRAPHICS]