A pilot randomized control trial to assess the adjunctive effect of diet on response to advanced therapies in patients with UC.

Abstract

Diet may influence ulcerative colitis (UC), but its impact on medication response remains unclear. We examined whether two 5-day cycles of a low-calorie, plant-based fasting-mimicking diet (LC-PB) could improve UC response to medications in a controlled trial.

Methods: Adults with active UC starting advanced therapies were randomized to LC-PB + therapy or control diet + therapy. The LC-PB diet provided 1,090 kcal on day one and 725 kcal on days 2-5. SCCAI was assessed at baseline and week 8. The study, planned for 60 patients, ended early due to COVID-19. The primary endpoint was clinical response (week 8, SCCAI decrease ≥ 3). Secondary outcomes were clinical improvement (change in SCCAI from baseline), steroid tapering, C-reactive protein (CRP), serum amyloid A (SAA), and FC (FC).

Results: Of 32 enrolled patients, 23 completed the study. In ITT, 57% in the LC-PB arm (8/14) achieved clinical response by week 8 vs. 35% in controls (6/17, p = 0.11). Secondary analyses indicated greater clinical improvement, measured as continuous SCCAI, in the LC-PB compared to control group (p = .039). The LC-PB group had better SCCAI sub-scores (i.e. urgency, well-being), reductions in SAA and were tapered off steroids compared to controls. Mean CRP and FC decreased more on the LC-PB, but results were not significant. There were no serious adverse events relating to the diet and no weight loss.

Conclusion: The LC-PB diet did not improve clinical response to medications. However, it led to clinical improvement, steroid tapering, and reduced SAA. As results were limited by sample size, larger studies are needed.