Profile of the glycolipid carbohydrate chains in the different epithelial regions of digestive tract and their involvement in synbiosis and infection of bacteria

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In murine digestive tract, glycolipids were differentially distributed in the different regions, i.e. the globo-series glycolipids including Forssman antigens in the mesenchymal regions and the ganglio-series glycolipids in the epithelial regions. Under germ-free condition, Gg_4Cer was the dominant glycolipid in the epithelia of duodenum, jejunum and ileum, but IV^2Fuα-Gg_4Cer became the major one after transfer of mice to the conventional breeding condition. However, the gastric and colonic epithelia contained GM1, fucosyl GMl, Gg_4cer and IV^2Fucα-Gg_4Cer, whose amounts were not affected by the breeding conditions. The gene responsible for fucosylation of Gg_4Cer in the digestive tract was characterized to be Fut-2 by targeted deletion of Fut-1 and Fut-2 genes. Also, although fucosylated glycolipids were completely eliminated from the stomach, caecum and colon of Fut-2-null mice, they were detected in the small intestine, indicating the alterative utilization of Fut-1 gene in the small intestine.Since Gg_4Cer is known to be the receptor of Lactobacillus, antibodies against L. johnsonii and L .intestinalis were generated to determine the binding ability of glycolipids and the number of bacteria in the different region of digestive tract. The antibodies reacted with teichoic acid in the cell wall of bacteria and with Gg_4Cer in the digestive tract, indicating the possible involvement of bacterial infection in the onset and progress of human disease with anti-Gg_4Cer antibodies, such as Beret disease, and that careful application of antibodies is required for the binding analysis of bacteria with Gg_4Cer.