Binding of Bifidobacterium bifidum and Lactobacillus reuteri to the carbohydrate moieties of intestinal glycolipids recognized by peanut agglutinin

We examined binding of Bifidobacterium bifidum and Lactobacillus reuteri to the carbohydrate moieties of glycolipids extracted from human enterocyte-like Caco-2 cells in this study. In binding assays to reference glycolipids of different carbohydrate compositions, B. bifidunt EB102 bound strongly to gangliotetraosyleeramide (asialo-GM1) and less strongly to gangliotriaosylceramide (asialo-GM2), lactosylceramide and sulfatide. The binding profile of B. bifidum EB102 was almost identical to that of L. reuteri JCM1081 described previously [Lett. Appl. Microbiol. 27 (1998) 130]. When we examined binding to neutral glycolipids extracted from Caco-2 cells, the binding profiles of B. b fidunt EB102 and L. reuteri JCM1081 were very similar to that shown by peanut agglutinin (PNA). Binding of both strains to periodate-treated intestinal glycolipids was completely abolished, suggesting that the bacterial cells bind to carbohydrate moieties of the glycolipids. Furthermore, B. bifidum EB102 was found to express multiple glycolipid-binding proteinaceaous components on the cell surface. These results strongly suggested involvement of cell-surface proteinaceous components of B. bifidunt in binding to the carbohydrate moieties of intestinal glycolipids recognized by PNA. Binding ability of B. bifidunt and L. reuteri to intestinal glycolipids may play a crucial role for colonization on the mucosal surface of the intestine. (C) 2003 Elsevier B.V. All rights reserved.