Ulcerative colitis (UC) is frequently treated with 5-ASA in active disease or to maintain remission. As dietary fibres binds 5-ASA in vitro, we wanted to investigate if a daily supplement of 30 ml of Isphagula Husk in patients with UC in remission or relapse affects disease activity and urinary excretion of 5-ASA.
It is a paired intervention study (trial I) and randomised controlled trial (trial II). The participants with UC in remission received 30 ml of fibre/day (trial I). Participants with relapsing UC were randomised to either 30 ml of fibre or blended breadcrumbs for two-three months (trial II).
The main outcome measures is C-reactive protein and 24 hours’ urine collection of total 5-ASA (trial I). In trial II the disease activity was determined by Inflammatory Bowel Disease Questionnaire (IBDQ) and Simple clinical colitis activity index (SCCAI) questionnaires.
22 participants with UC in remission and 12 with relapsing UC were included. In trial I no significant effect of fibre on CRP or on disease activity was found, whereas a decreased urinary excretion by a median of 6.3 percentage point (range: -50.6-33.6; p=0.03) of total 5-ASA was found. No significant differences were found between fibre and placebo groups in trial II.
A decreased urinary excretion of total 5-ASA was seen in patients with UC in remission, but not in patients with relapsing UC. The number of patients was low and different factors could affect the results, but the results confirm that the in vitro results can be reproduced in patients.