Inhibitory Effects of Bifidobacterium longum on Experimental Ulcerative Colitis Induced in Mice by Synthetic Dextran Sulfate Sodium

Background/Aims: The relationship between alterations in intestinal microflora and ulcerative colitis is still not clear. Whether improvement in bacterial populations might be a new strategy for prevention or treatment needs to be tested. Methods: Ulcerative colitis was induced in mice by oral administration of synthetic dextran sulfate sodium (molecular weight 54,000). Inhibitory effects of concomitant treatment with Bifidobacterium longum were assessed in terms of total colon length and severity of histological changes. In addition, changes of microflora and short-chain fatty acids were tested in fecal samples and compared before and after treatment. Results: Administration of B. longum significantly inhibited both shortening of total colon length and the severity of ulcerative colitis compared to controls. It was confirmed that the administered B. longum resided in the gut and blocked the decrease of lactobacilli in fecal samples in mice with dextran sulfate sodium-induced colitis. Conclusions: Oral administration of B. longum exerts marked inhibitory effects on ulcerative colitis in mice.