Diarrhea is a common problem in children worldwide and in particular in the socioeconomically developing world where more than one billion diarrhea episodes with an estimated 2 to 2.5 million deaths occur every year (O’Ryan et al. 2005). One of the significant causes of diarrhea is the group of Diarrheagenic E. coli. Among these Enterohemorrhagic Escherichia coli (EHEC) have recently been recognized as an emerging food-borne pathogen (Kaper et al. 2004). Here the molecular effects of the interaction between the probiotic Nissle and various EHEC strains is analysed.