A Starch- and Sucrose-Reduced Diet Has Similar Efficiency as Low FODMAP in IBS—A Randomized Non-Inferiority Study

A diet with low content of fermentable oligo-, di-, and monosaccharides and polyols (FODMAP) is established treatment for irritable bowel syndrome (IBS), with well-documented efficiency. A starch- and sucrose-reduced diet (SSRD) has shown similar promising effects. The primary aim of this randomized, non-inferiority study was to test SSRD against low FODMAP and compare the responder rates (RR = ∆Total IBS-SSS ≥ -50) to a 4-week dietary intervention of either diet. Secondary aims were to estimate responders of ≥100 score and 50% reduction; effects on extraintestinal symptoms; saturation; sugar craving; anthropometric parameters; and blood pressure. 155 IBS patients were randomized to SSRD (n = 77) or low FODMAP (n = 78) for 4 weeks, with a follow-up 5 months later without food restrictions. The questionnaires Rome IV, IBS-severity scoring system (IBS-SSS), and visual analog scale for IBS (VAS-IBS) were completed at baseline and after 2 and 4 weeks and 6 months. Weight, height, waist circumference, and blood pressures were measured. Comparisons were made within the groups and between changes in the two groups. There were no differences between groups at baseline. The responder rate of SSRD was non-inferior compared with low FODMAPs at week 2 (79.2% vs. 73.1%; <i>p</i> = 0.661;95% confidence interval (CI) = -20-7.2) and week 4 (79.2% vs. 78.2%; <i>p</i> = 1.000;95%CI = -14-12). Responder rate was still high when defined stricter. All gastrointestinal and extraintestinal symptoms were equally improved (<i>p</i> < 0.001 in most variables). SSRD rendered greater reductions in weight (<i>p</i> = 0.006), body mass index (BMI) (<i>p</i> = 0.005), and sugar craving (<i>p</i> = 0.05), whereas waist circumference and blood pressure were equally decreased. Weight and BMI were regained at follow-up. In the SSRD group, responders at 6 months still had lowered weight (-0.7 (-2.5-0.1) vs. 0.2 (-0.7-2.2) kg; <i>p</i> = 0.005) and BMI (-0.25 (-0.85-0.03) vs. 0.07 (-0.35-0.77) kg/m²; <i>p</i> = 0.009) compared with baseline in contrast to non-responders. Those who had tested both diets preferred SSRD (<i>p</i> = 0.032). In conclusion, a 4-week SSRD intervention was non-inferior to low FODMAP regarding responder rates of gastrointestinal IBS symptoms. Furthermore, strong reductions of extraintestinal symptoms were found in both groups, whereas reductions in weight, BMI, and sugar craving were most pronounced following SSRD.