Improved lipid and glycemic profile and vitamin D levels after a dietary intervention with SSRD and low FODMAP in IBS patients: A randomized controlled trial

Abstract

Background: Irritable bowel syndrome (IBS) is the most common disorder of gut-brain interaction and associated with overweight. Low content of fermentable oligo-, di-, and monosaccharides and polyols (FODMAP) and a starch- and sucrose-reduced diet (SSRD) alleviate IBS symptoms, but restrictive diets may lead to malnutrition. The aim of the present clinical trial was to randomize IBS patients to either SSRD or low FODMAP and compare circulating metabolic and nutritional status over time.

Methods: Of 155 included patients, 77 received SSRD and 78 low FODMAP for 4 weeks, with a follow-up at 6 months. Study and Rome IV questionnaires, food diary, IBS-severity scoring system, and visual analog scale for IBS were completed, along with blood sampling and anthropometric measurements. Albumin, C-reactive peptide, glycosylated hemoglobin A1c (HbA1c) (mmol/mol), lipid profile (mmol/L), and micronutrients were analyzed in plasma/serum.

Results: Both diets improved gastrointestinal and extraintestinal symptoms. The weight reduction was most pronounced in SSRD (-1.6(-2.4 to [-0.4] kg vs. -0.8(-1.6 to [-0.1] kg; P = 0.006). Cholesterol (-0.1(-0.5 to 0.1), P = 0.007; -0.2(-0.4 to 0.1), P = 0.009), low-density lipoprotein (LDL) (-0.2(-0.4 to 0.1), P = 0.004; -0.1(-0.4 to 0.1), P = 0.017), and non-high-density lipoprotein (non-HDL) (-0.1(-0.4 to 0.1), P = 0.015; -0.1(-0.4 to 0.1), P = 0.008) decreased at week 4 and month 6 in the SSRD group, but only after 4 weeks in the low FODMAP group (-0.2(-0.5 to 0.2), P = 0.003; -0.1(-0.3 to 0.1), P = 0.036; and -0.2(-0.4 to 0.1), P = 0.002, respectively). At week 4, HbA1c decreased (0(-1.0 to 0), P = 0.010 and (0(-1.0 to 0), P = 0.009) and vitamin D increased (6(-3 to 16) nmol/L, P = 0.004 and 4(-5 to 14) nmol/L, P = 0.017) in both groups, with continued elevated vitamin D levels after SSRD. Folate increased and iron decreased in the SSRD group. Lower calcium and ferritin levels were found after low FODMAP. At 6 months, cobalamin was lower in both groups.

Conclusions: SSRD and low FODMAP improve symptoms and the lipid, glycemic, and vitamin D profiles. The improved lipid and vitamin D profiles remained at follow-up in the SSRD group.

Keywords: Dietary habits; HbA1c; Irritable bowel syndrome; Lipid profile; Low FODMAP; Starch- and sucrose-reduced diet (SSRD, Randomized controlled trial (RCT).