Escherichia coli Nissle 1917

Escherichia coli strain Nissle 1917 (EcN) is a remarkable probiotic bacterium, first described by Alfred Nissle in 1916/17. As the active component of Mutaflor, EcN has been well researched over decades but detailed mechanisms by which EcN confers its probiotic effects are still elusive. EcN however, has a unique profile concerning fitness factors in the absence of any virulence factors. In several large clinical trials EcN demonstrates statistical equivalence with mesalazine in the maintenance of remission of ulcerative colitis. Also, efficacy was shown in the treatment of acute and chronic diarrhea in toddlers and children. Less convincing are the data concerning the treatment of Crohn’s disease and irritable bowel syndrome. More recently, EcN, due to its innocuous nature has been used as a delivery vehicle for vaccines, cytokines, and other substances. This chapter aims to provide an overview of clinical applications and mechanisms responsible for the observed effects.