Gluten and fructan intake and their associations with gastrointestinal symptoms in irritable bowel syndrome: A food diary study

Abstract

Wheat contains several components, including gluten and fructan, that may be associated with gastrointestinal symptoms (GI) in irritable bowel syndrome (IBS). The aims of the study were to determine the average daily intake of gluten, investigate the association of gluten and GI symptoms, as well as the association between fructan and GI symptoms in IBS subjects. We assessed dietary intake, including total energy, and calculated average gluten and fructan intake in this 4-day food diary study. The subjects reported GI symptoms using the validated Gastrointestinal Symptom Rating Scale-IBS (GSRS-IBS). In total, 147 IBS subjects (116 females) were included in this study. The median (IQR) intake of gluten was 11.0 (7.5-15.4) (range: 0.6-52.1) g/day, and this intake was significantly higher for males (16.2 (11.5-18.8), g/day) compared with females (10.3 (7.3-13.2), g/day) (P≤0.001). For analyses purposes, the subjects were stratified in tertiles of gluten intake. Median (IQR) overall GI symptom severity (GSRS-IBS) was significantly worse for the subjects with the lowest (52 (45-57)) and intermediate gluten intake (51 (43-58)), compared with the highest gluten intake (45 (37-50), P≤0.05, and P≤0.01 respectively). In addition, caloric intake was significantly lower in subjects with the lowest (1905±446, kcal/day) and intermediate gluten intake (1854±432, kcal/day), compared with subjects with the highest gluten intake (2305±411, kcal/day), P<0.001 for both. Analyses of the stratified fructan tertiles resulted in no significant differences in GSRS-IBS. The mean intake of gluten varies substantially among subjects with IBS, and IBS subjects with more severe GI symptoms have lower intake of gluten and calories. (http://www.clinicaltrials.gov): Registered under Clinical Trial number NCT02970591.