Double-blind comparison of an oral Escherichia coli preparation and mesalazine in maintaining remission of ulcerative colitis

Background: Aminosalicylates are used as standard treatment for maintaining remission in ulcerative colitis. As yet, there is no other existing alternative with proven efficacy. In light of the hypothesis that the intestinal environment map contribute to the pathophysiology of ulcerative colitis, a trial was conducted to test the effects of probiotic treatment with an oral preparation of non-pathogenic E. coli. Methods: A total of 120 patients with inactive ulcerative colitis were included in a double-blind, double-dummy study comparing mesalazine 500 mg t.d.s. to an oral preparation of viable E. coli strain Nissle (Serotype 06: K5: H1) for 12 weeks with regard to their efficacy in preventing a relapse of the disease, Study objectives were to assess the equivalence of the clinical activity index (CAI) under the two treatment modalities and to compare relapse rates, relapse-free times and global assessment, Results: The start and end scores of the CAI demonstrated no significant difference (P = 0.12) between the two treatment groups. Relapse rates were 11.3% under mesalazine and 16.0% under E. coli Nissle 1917 (N.S.). Life table analysis showed a relapse-free time of 103 +/- 4 days for mesalazine and 106 +/- 5 days for E. coli Nissle 1917 (N.S.). Global assessment was similar for both groups. Tolerability to the treatment was excellent and did not differ, No serious adverse events were reported. Conclusions: From the results of this preliminary study, probiotic treatment appears to offer another option for maintenance therapy of ulcerative colitis. Additional support is provided for the hypothesis of a pathophysiological role for the intestinal environment in ulcerative colitis.