Therapeutic Potential of the 4 Strategies to SUlfide-REduction (4-SURE) Diet in Adults with Mild to Moderately Active Ulcerative Colitis: An Open-Label Feasibility Study

Diet therapy may bridge the therapeutic gap in ulcerative colitis (UC). The novel 4-SURE diet (4-strategies-to-SUlfide-REduction), designed to modulate colonic fermentation and influence production of excess hydrogen sulfide, was examined in a feasibility study for tolerability, clinical efficacy, and effects on microbial endpoints. Adults aged ≥18 y old with mild to moderately active UC were advised to increase intake of fermentable fibers, restrict total and sulfur-containing proteins, and avoid specific food additives for 8 wk. The primary outcome was tolerability of diet [100-mm visual analogue scale (VAS) with 100-mm being intolerable]. Secondary exploratory outcomes were self-reported adherence (always adherent ≥76–100%), clinical and endoscopic response (reduction in partial Mayo ≥2 and Mayo endoscopic subscore ≥1), modulation of fecal characteristics including markers of protein and carbohydrate fermentation, and food-related quality of life (IBD-FRQoL-29). Primary analysis was by intention to treat, performed using paired t and Wilcoxon signed-rank statistical tests. Twenty-eight adults with UC [mean (range) age: 42 (22–72) y, 15 females, 3 proctitis, 14 left-sided, and 11 extensive] were studied. Prescribed dietary targets were achieved overall. The diet was well tolerated (VAS: 19 mm; 95% CI: 7, 31 mm) with 95% frequently or always adherent. Clinical response occurred in 13 of 28 (46%) and endoscopic improvement in 10 of 28 participants (36%). Two participants (7%) worsened. Fecal excretion of SCFAs increased by 69% (P < 0.0001), whereas the proportion of branched-chain fatty acids to SCFAs was suppressed by 27% (–1.34%; 95% CI: –2.28%, –0.40%; P = 0.007). The FRQoL improved by 10 points (95% CI: 4, 16; P < 0.001). The 4-SURE dietary strategy is considered tolerable and an acceptable diet by adults with mild to moderately active UC. The dietary teachings achieved the prescribed dietary and fecal targets. Given signals of therapeutic efficacy, further evaluation of this diet is warranted in a placebo-controlled trial. This trial was registered at www.anzctr.org.au (Australian New Zealand Clinical Trials Registry) as ACTRN12619000063112.