Administration of riboflavin-producing lactic acid bacteria prevents TNBS-induced colitis in mice

Abstract

The pathogenesis of inflammatory bowel diseases is not fully understood; however several studies have proposed the overproduction of reactive oxygen species (ROS) as a key factor in their development. It has been shown that certain strains of acid lactic bacteria can produce beneficial compounds in foods or in the gastrointestinal tract including riboflavin, a vitamin with reported antioxidant and antiinflammatory actions. The aim of this study was to evaluate the effect of administration of soymilk fermented by a riboflavin-producing strain and also probiotic suspensions of different riboflavin-producing strains in a colitis mouse model. Mice were intrarectally inoculated with TNBS to induce intestinal inflammation or with ethanol for the control, and they were orally administered with soymilk fermented by Lactobacillus plantarum CRL2130 or individual suspensions of L. plantarum CRL2130, L. paracasei CRL76, L. bulgaricus CRL871, and Streptococcus thermophilus CRL803. Weight loss, intestinal damage and number of iNOs+ cells, microbial translocation to liver and cytokines levels in intestinal fluids were evaluated. Results showed that administration of both the soymilk fermented by L. plantarum CRL2130 and either one of the four riboflavin-producing strains reduce the intestinal damage caused by TNBS compared to controls given unfermented soymilk, soymilk fermented by a non-riboflavin-producing strain and non-bacterial treatment. Administration of commercial riboflavin showed similar beneficial effects. An immunomodulatory property, with elevated production of IL-10 was associated to L. paracasei CRL76, in addition to riboflavin production. In conclusion our results show that the administration of riboflavin-producing strains can prevent colitis in mice either when administered in a food matrix or as probiotic suspension suggesting its possible use in a pharmaceutical formulation.