Evaluation of therapeutic properties of fermented vegetables extract (OM-X®) in the model of colitis induced by Citrobacter rodentium in mice

•OM-X™ is prepared by fermentation of vegetables, fruits, seaweeds and mushrooms.•OM-X™ reduces gut epithelium damage in Citrobacter-induced colitis in mice.•OM-X™ increases expression of tight-junction genes, decreases bacterial translocation.•The effects of OM-X™ may be mediated by a reduction of Clostridium bacteria counts. Infection of mice with Citrobacter rodentium serves as a model to study human intestinal infections. C. rodentium infection leads to increased production of inflammatory cytokines, immune cell infiltration and damage to the gut barrier. We used this model of colitis to evaluate the therapeutic properties of OM-X®, an extract prepared by fermentation of vegetables, seaweeds, fruits and mushrooms. Administration of OM-X® to C. rodentium-infected mice reduced damage to the intestinal epithelium, lowered inflammation scores, increased IL-10 expression and maintained FoxP3 gene expression. OM-X® also partially prevented bacterial translocation, increased expression of tight junction genes and increased proliferation of epithelial cells. PCR analysis of stool samples showed that OM-X® significantly reduced the populations of bacteria harboring buk gene (mostly Clostridium species). It is suggested that alterations of microbiota composition, following OM-X® consumption, contribute to protection against infection and epithelial damage, and lead to an increased expression of anti-inflammatory cytokines.