Effects of a Lactobacillus reuteri BR11 Mutant Deficient in the Cystine-Transport System in a Rat Model of Inflammatory Bowel Disease

Background Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract associated with altered composition of the gut microbiota. Lactobacillus reuteri BR11 (BR11) has recently been reported to reduce the severity of experimental IBD because of its probiotic properties possibly attributed to a mechanism of thiol production via its unique cysteine/cystine-transport system. Aim We compared BR11 and a BR11 mutant deficient in the cystine-uptake system (PNG201), for their capacity to reduce the severity of experimental colitis. Methods Male Sprague–Dawley rats ( n = 8 per group) were gavaged (1 ml/day) with skim milk, BR11 or PNG201 (1 × 10 9 CFU/ml) for 12 days. Rats consumed either water or 2% dextran sulfate sodium in drinking water from days 6 to 12 to induce colitis. Metabolism data, disease activity index, intestinal mucin profile, and histological analyses were assessed and compared by ANOVA. Results Assessed histologically, DSS administration resulted in significant colonic deterioration, including loss of crypt area and increased damage severity. BR11 administration only partially alleviated the DSS effects, with a minor improvement in crypt area ( P 0.05) against the DSS control for any of the end-points. However, the mutant strain induced significantly greater ( P