VSL#3 induces and maintains shortterm clinical response in patients with active microscopic colitis: a two-phase randomised clinical trial

Background: The probiotic mixture VSL#3 has proven efficacious in inflammatory bowel diseases and irritable bowel syndrome; however, its efficacy in microscopic colitis (MC) is being investigated. Objective: To evaluate the safety and efficacy of a multistrain probiotic, VSL#3, in inducing clinical remission and achieving clinical response, as compared with mesalamine, in patients with active MC. Methods: A randomised, open labelled study comparing the efficacy of 900 billion colony-forming units/day of VSL#3 (group (Gp) A) or 1.6 g of mesalamine/day (Gp B) for 8 weeks in 30 patients with MC was conducted. After a washout period of 2 weeks, Gp B received 8 weeks of VSL#3 and Gp A was off medication for the next 8 weeks. The primary end points were clinical remission and clinical response at 8 weeks. Results: Of 30 patients, 15 were randomised in each arm. 11 patients in Gp A and 13 patients in Gp B completed 8 weeks of treatment. 5 (46%) of 11 patients in Gp A and 1 (8%) of 13 patients in Gp B attained clinical remission (p=0.022). Clinical response was seen in Gp A, as evidenced by a lower stool weight (377.6 +/- 104.5 g) as compared with Gp B (507 +/- 168.2 g; p=0.03). VSL#3 was effective in maintaining clinical response up to 10 weeks, even after discontinuation of therapy. Secondary end points like stool parameters, histology and well-being improved in both treatment groups. Conclusions: The probiotic VSL#3 was found to offer the benefit of inducing as well as maintaining shortterm clinical response in patients with active MC.