The effect of selenium supplementation on disease activity and immune-inflammatory biomarkers in patients with mild-to-moderate ulcerative colitis: a randomized, double-blind, placebo-controlled clinical trial

Purpose Selenium (Se) supplementation may help reduce inflammation and disease activity in ulcerative colitis (UC) patients. We investigated the therapeutic effects of Se administration in cases with mild-to-moderate active UC. Methods A multicenter, double-blind, randomized clinical trial (RCT) was conducted on 100 cases with active mild-to-moderate UC. The patients were randomly allocated to be given an oral selenomethionine capsule (200 mcg/day, n = 50) or a placebo capsule ( n = 50) for 10 weeks. The primary outcome was defined as disease activity via the Simple Clinical Colitis Activity Index (SCCAI), and secondary outcomes were measured at the end of the study. Results After 10 weeks, the SCCAI score's mean was reduced in the Se group ( P < 0.001). At the end of the intervention, clinical improvement (decline of 3 ≥ score from baseline score) was observed in 19 patients (38%) of the Se group and 3 patients (6%) of the placebo group. The patients with clinical remission (defined as SCCAI ≤ 2) were assigned in the Se group ( P = 0.014). The Se group’s quality of life and Se serum levels were enhanced at the end of the study ( P < 0/001). In the Se group, the mean concentration of interleukin-17 decreased ( P < 0/001). However, the levels of interleukin-10 showed no considerable change between the two groups in the 10th week ( P = 0.23). Conclusion Se supplementation as add-on therapy with medical management induced remission and improved the quality of life in patients with active mild-to-moderate UC. Trial registration number and date of registration IRCT20091114002709N51; 2020-04-13.