P476 Fermentable carbohydrates (FODMAPs) as triggers of functional gastrointestinal symptoms in patients with quiescent inflammatory bowel disease: a double-blind, placebo-controlled, randomised, cross-over re-challenge trial
S. Cox*1, A. Prince1, 2, C. Myers1, 3, P. M. Irving1, 4, J. O. Lindsay5, M. C. Lomer1, 4, K. Whelan1
1King’s College London, School of Medicine, Diabetes and Nutritional Sciences Division, London, United Kingdom, 2King’s College Hospital NHS Foundation Trust, Nutrition and Dietetics, London, United Kingdom, 3The Royal Surrey County Hospital NHS Trust, Nutrition and Dietetics, Guildford, United Kingdom, 4Guy’s and St Thomas’ NHS Foundation Trust, Gastroenterology, London, United Kingdom, 5Barts Health NHS Trust, Gastroenterology, London, United Kingdom
There is preliminary evidence that the ‘low FODMAP’ diet may ameliorate functional gastrointestinal symptoms (FGS) in quiescent inflammatory bowel disease (IBD); however, whether fermentable carbohydrates induce FGS in IBD is unknown. Our aim was to determine whether individual fermentable carbohydrates induce FGS in IBD using a double-blinded, placebo-controlled, randomised, cross-over re-challenge trial.
Patients with IBD in clinical and biochemical remission and with co-existent FGS responsive to a low FODMAP diet were allocated in random order to a series of 3-day fermentable carbohydrate challenges provided at plausible dietary doses (fructans 12 g/d; galacto-oligosaccharides [GOS] 6g/d; and sorbitol 6 g/d) and glucose placebo 12 g/d. Each 3-day challenge was separated by a 4-day washout period. During the 3-day challenges, symptoms were measured daily using the Global Symptom Question (adequate relief of FGS) and the Gastrointestinal Symptom Rating Scale, and stool output was measured using the Bristol Stool Form Scale. Data were compared between the challenge arms using Friedman’s test and repeated measures ANOVA and Bonferroni post-hoc adjustment, as appropriate.
In total, 32 patients with IBD were recruited, and data were available for 29 patients who completed all arms of the trial (12 Crohn’s and 17 ulcerative colitis; mean age 40.1 ± 14.4 years; 32% male). All met Rome III criteria for irritable bowel syndrome (n = 12), functional bloating (n = 12), or functional diarrhoea (n = 5). There was no significant difference in the number of days of adequate relief reported across the challenges (p = 0.057). During the fructan challenge compared with placebo (glucose), there were significantly more days of moderate or severe pain (0.9 vs 0.2, p = 0.014), bloating (1.0 vs 0.3, p = 0.017), and flatulence (1.2 vs 0.4, p = 0.034). Compared to placebo (3.5, SD 1.0), there was a significant difference in mean stool consistency during the fructan (4.2, SD 1.3, p = 0.007) and GOS challenges (4.0, SD 1.0, p = 0.033). There were no significant differences in any other symptoms, or for any symptoms during the GOS or sorbitol challenges, compared with placebo.
Fructans, but not GOS or sorbitol, induced FGS in patients with quiescent IBD. These findings are consistent with those of a re-challenge trial in irritable bowel syndrome that also demonstrated induction of gastrointestinal symptoms following fructan re-challenge. Further research is required to determine the effects of fermentable carbohydrate dose on FGS in IBD, and whether a low FODMAP diet is effective in managing FGS in IBD in clinical practice.