ANTIULCER EFFECTS OF LACTIC-ACID BACTERIA AND THEIR CELL-WALL POLYSACCHARIDES

The anti-ulcer effects of bifidobacteria, lactobacilli and streptococc i were examined using the acetic acid-induced gastric ulcer and ethano l-induced erosion models in rats. Bifidobacterium breve YIT4014 and 40 43, and Bifidobacterium bifidum YIT4007 were administered orally, and anti-ulcer effects were confirmed for not only these organisms but als o their polysaccharide fractions (PSFs). The major component of these anti-ulcer polysaccharides was rhamnose. In particular, polysaccharide s in which the rhamnose content exceeded 60% were more effective in he aling gastric ulcers. After administration of the PSF from B. bifidum YIT4007, the levels of epidermal growth factor and basic fibroblast gr owth factor increased in gastric tissues. Similar results were observe d for the culture supernatant of gastric epithelial cells cultured wit h PSF. Furthermore, the production of 6-ketoprostaglandin F-1 alpha by macrophages was also enhanced by PSF. These results indicated that th ese bacteria and their polysaccharides induced host repair and protect ive systems in the gastric ulcer model.