We examined the competition of bind

We examined the competition of binding of Lactobacillus reuteri and Helicobacter pylori to gangliotetraosylceramide (asialo-GM1) and
sulfatide which are putative glycolipid receptor molecules of H. pylori, and identified a possible sulfatide-binding protein of the L. reuteri
strain. Among nine L. reuteri strains, two (JCM1081 and TM105) were shown to bind to asialo-GM1 and sulfatide, and to inhibit binding of
H. pylori to both glycolipids by a thin layer chromatogram-overlay assay using biotin-labeled bacterial cells. The extract from the bacterial
cells of strain TM105 with several detergents, including octyl L-D-glucopyranoside, retained binding to both glycolipids and also inhibited
H. pylori binding, suggesting that a binding inhibitor(s) is associated with the bacterial cell surface. When the cell extract was applied to the
agarose gel immobilized galactose 3-sulfate corresponding to the structure of sugar moieties of sulfatide, an approximately 47-kDa protein
was found to bind to the gel. This observation strongly suggested that inhibition by selected L. reuteri strains help to prevent infection in an
early stage of colonization in H. pylori and proposed that L. reuteri strains sharing glycolipid specificity with H. pylori have a potential as
probiotics. ß 2002 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.