The pathogenic mechanism of inflammatory bowel diseases is not fully understood but colonic microflora including Lactobacillus and Bifidobacterium species may affect the induction of colonic inflammation. In this study the relative efficacy of different probiotic organisms in the prevention of colitis was compared in an induced rat colitis model. Three Lactobacillus strains and two Bifidobacterium strains were fed to Sprague–Dawley rats for 7 days prior to offering the rats 5% dextran sulfate sodium (DSS) in their drinking water to induce colitis and the administration of the probiotics continued for 7 days with the DSS. Colitis severity was assessed daily using a disease activity index (DAI). Samples were collected 7 days after colitis induction for intestinal bacterial flora and bacterial translocation. The DAI decreased significantly on days 4, 5, 6, and 7 in the Lactobacillusplantarum DSM 9843, Bifidobacterium sp. 3B1, and Bifidobacterium infantis DSM 15158 groups compared to the colitis control. It decreased significantly on days 5, 6, and 7 in the Bifidobacterium infantis DSM 15158 group compared to the Lactobacillus paracaesi DSM 13434 and Lactobacillus gasseri 5B3 groups. It also decreased significantly on day 7 in the L. plantarum DSM 9843 group compared to the L. gasseri 5B3 group. Bacterial translocation to the mesenteric lymph nodes decreased significantly in all treatment groups compared to the colitis control. Enterobacteriaceae bacterial translocation to the liver decreased in all treatment groups compared to the colitis control. Administration of certain strains of Lactobacillusand Bifidobacterium significantly improves the DAI and reduces bacterial translocation, and L. plantarum DSM 9843, Bifidobacterium sp. 3B1, and Bifidobacterium infantis DSM 15158 seem to have the best effect.
