THE EFFECTS OF LACTOBACILLUS STRAINS AND OAT FIBER ON METHOTREXATE-INDUCED ENTEROCOLITIS IN RATS

Background & Aims: Administration of methotrexate to rats on an elemen tal diet results in severe enterocolitis and death. Lactobacilli, an i ntegral part of the healthy gastrointestinal microecology, may provide therapeutic benefits to help the recovery from enterocolitis. The pur pose of this study was to evaluate the effects of lactobacilli and oat base on methotrexate-induced enterocolitis in rats. Methods: Rats rece ived continuous intragastric infusion of elemental diet or with supple mentation of oatbase, Lactobacillus reuteri R2LC, and Lactobacillus pl antarum DSM 9843, with and without fermentation, from the beginning of the study. Methotrexate (20 mg/kg) was injected intraperitoneally on day 3, and the sampling was performed on day 6. Results: Lactobacilli and oatbase decreased body weight loss and intestinal permeability and increased bowel mucosal mass in enterocolitic rats. Administration of lactobacilli, but not oatbase, decreased the intestinal myeloperoxida se level, reestablished intestinal microecology, and reduced bacterial translocation to extraintestinal sites. Both lactobacilli and oatbase reduced plasma endotoxin levels. The effects of lactobacilli were gre ater with fermentation than without fermentation or oatbase alone, and L. plantarum was move effective in reducing intestinal pathogens than L. reuteri. Conclusions: Exogenous administration of lactobacilli, es pecially L. plantarum with fermentation, is helpful in reducing the se verity of enterocolitis in rats.