Background : Probiotics are efficacious for treating and maintaining remission of ulcerative colitis.

Aim : To conduct a randomized placebo‐controlled trial of bifidobacteria‐fermented milk supplementation as a dietary adjunct in treating active ulcerative colitis.

Methods : Twenty patients with mild to moderate, active, ulcerative colitis randomly received 100 mL/day of bifidobacteria‐fermented milk or placebo for 12 weeks with conventional treatment.

Results : Clinical and endoscopic activity indices and histological scores were similar in the two groups before treatment. Although improvements were significant in both groups, the clinical activity index was significantly lower in the bifidobacteria‐fermented milk than in the placebo group after treatment. The post‐treatment endoscopic activity index and histological score were significantly reduced in the bifidobacteria‐fermented milk, but not the placebo group. Increases in faecal butyrate, propionate and short‐chain fatty acid concentrations were significant in the bifidobacteria‐fermented milk, but not the placebo group. No adverse effects were observed in either group.

Conclusion : Supplementation with this bifidobacteria‐fermented milk product is safe and more effective than conventional treatment alone, suggesting possible beneficial effects in managing active ulcerative colitis. This is a pilot study and further larger studies are required to confirm the result these preliminary results.