Role and mechanisms of action of Escherichia coli Nissle 1917 in the maintenance of remission in ulcerative colitis patients: An update.

Ulcerative colitis (UC) is a chronic inflammatory disease, whose etiology is still unclear. Its pathogenesis involves an interaction between genetic factors, immune response and the "forgotten organ", Gut Microbiota. Several studies have been conducted to assess the role of antibiotics and probiotics as additional or alternative therapies for Ulcerative Colitis. Escherichia coli Nissle (EcN) is a nonpathogenic Gram-negative strain isolated in 1917 by Alfred Nissle and it is the active component of microbial drug Mutaflor(®) (Ardeypharm GmbH, Herdecke, Germany and EcN, Cadigroup, In Italy) used in many gastrointestinal disorder including diarrhea, uncomplicated diverticular disease and UC. It is the only probiotic recommended in ECCO guidelines as effective alternative to mesalazine in maintenance of remission in UC patients. In this review we propose an update on the role of EcN 1917 in maintenance of remission in UC patients, including data about efficacy and safety. Further studies may be helpful for this subject to further the full use of potential of EcN.

Locally injected Infliximab ameliorates murine DSS colitis: differences in serum and intestinal levels of drug between healthy and colitic mice.

BACKGROUND: Infliximab is effective in human and murine IBD, but its pharmacodynamic is still poorly known. The aim of this study was to assess the affinity of infliximab to murine TNF-α, its role in murine colitis when administered intra-rectally and its levels in the blood, gut mucosa and stool of healthy and sick mice. METHODS: An ELISA kit was built in order to assess the affinity of infliximab to human or murine-TNF-α. Human IgG were used as controls. DSS model of colitis on C57BL/6 mice was used to assess clinical efficacy of infliximab administered intravenously or by enema. Stool, serum and colon samples were collected to assess infliximab levels and histology for Rachmilewitz score. RESULTS: Infliximab showed a good affinity both for human-TNF-α and murine-TNF-α. In DSS colitic mice infliximab ameliorated the severity of colitis, regardless of the administration route. In comparison with colitic mice, healthy mice displayed higher serum and mucosal infliximab levels, while detectable levels of infliximab were found in faeces, particularly in colitic mice. CONCLUSION: Our data support murine models to study infliximab pharmacokinetics and dynamics. Measurable levels of infliximab can be found at different concentrations in blood, intestinal mucosa and stool from healthy and sick mice, thus infliximab pharmacokinetics could have a major impact in human IBD.