Effects of bromelain supplementation on disease activity and quality of life in patients with ulcerative colitis: a randomized, triple-blind, placebo-controlled study

Bromelain is a proteolytic enzyme found in pineapple fruit. This study was conducted to evaluate the effects of bromelain supplementation on disease activity and quality of life (QoL) in patients with ulcerative colitis (UC). Seventy individuals with mild-to-moderate UC participated in a randomized, triple-blind clinical trial. Participants were randomly assigned to receive either maltodextrin as a placebo or 400 mg of bromelain daily for eight weeks. QoL and Simple Clinical Colitis Activity Index (SCCAI) scores were assessed. All results were analyzed using both intention-to-treat (ITT) and per-protocol (PP) approaches. The only demographic factor that differed between the two groups statistically significantly was gender (p = 0.01). Additionally, the mean difference in vitamin B6 consumption variations between the bromelain and placebo groups was significant (0.39 ± 0.86 vs. -0.44 ± 1.43; p < 0.001). There was no considerable difference detected for the other nutrients. The bromelain group had considerably higher changes in their SCCAI score in comparison with the placebo group (-3.29 ± 2.17 vs. -1.11 ± 1.71; p < 0.001). There was no considerable difference in changes in QoL questionnaire scores between the intervention and control groups (3.76 ± 6.18 vs. 3.91 ± 4.30; p = 0.90). After correcting for baseline, the findings remained significant for the SCCAI variable but not for the QoL variable (p < 0.001 and p = 0.99). In UC patients, the severity of the disease is reduced by bromelain supplementation, which is an alternative therapy.Trial registration: The study protocol received approval from the Ethics Committee at Iran University of Medical Sciences "IR.IUMS.REC.1402.125" and was registered with the Iranian Clinical Trials Registry "IRCT20191105045340N2" on 09/07/2023.