Abstract: The present invention relates to the treatment of diseases induced by Enterobacteriae. The inventors evaluated, in a multicellular in vitro model associating cells representing human enterocytes (Caco-2 cells), goblet mucus secreting cells (HT29-MTX) and M cells, whether Bacteroides fragilis, a non-enterotoxigenic strain, could be useful to limit the severity of the Salmonella Heidelberg infection, with an hypermutator phenotype, by analyzing their impact on growth and mucosal translocation. Thus, the present invention relates to a Bacteroides fragilis strain for use in the treatment of diseases induced by Enterobacteriae in a subject in need thereof.