Fermentable carbohydrates (FODMAPs) exacerbate functional gastrointestinal symptoms in patients with inflammatory bowel disease: a randomized double-blind, placebo controlled, cross-over, re-challenge trial.
Cox SR, Prince AC, Myers CE et al
Journal of Crohn’s and Colitis.
Doi :10.1093/ecco-jcc/jjx073
During periods of inflammatory bowel disease (IBD) remission, a significant proportion of patients continue to suffer from gastrointestinal symptoms not caused by active intestinal inflammation but which meet Rome criteria for functional bowel disorders. Persistent functional gastrointestinal symptoms (FGS), including abdominal pain, bloating, flatulence and diarrhoea may greatly impact on quality of life.
Journal of Crohn’s and Colitis.
Doi :10.1093/ecco-jcc/jjx073
During periods of inflammatory bowel disease (IBD) remission, a significant proportion of patients continue to suffer from gastrointestinal symptoms not caused by active intestinal inflammation but which meet Rome criteria for functional bowel disorders. Persistent functional gastrointestinal symptoms (FGS), including abdominal pain, bloating, flatulence and diarrhoea may greatly impact on quality of life.
The efficacy of the low FODMAP diet in patients with quiescent IBD and co-existing FGS has not been widely studied but preliminary evidence from uncontrolled trials is promising.
The aim of this study was to conduct a randomized, double-blinded, placebo-controlled, cross-over, re-challenge trial, designed to compare the effects of FODMAP challenges to a placebo (glucose) on FGS in patients with quiescent IBD, experiencing co-existent FGS.
Participants were recruited from gastroenterology clinics at Guy’s and St Thomas’ and Bart’s Hospitals. The inclusion criteria were a diagnosis of Crohn’s disease (CD) or ulcerative colitis (UC) at least 6 months prior to involvement and currently in remission. In addition, participants must have been experiencing FGS that met Rome III criteria for IBS and experienced a marked improvement following a low FODMAP diet. Eligible participants were allocated to a series of 4 FODMAP challenges in random order, each with a duration of 3 days and separated by a washout period of at least 4 days. The four challenges were: 12g/day of fructans; 6g/day GOS; 6g/day sorbitol and 12g/ day glucose (placebo). All challenges were taken as drinks and consumed once daily for 3 days. The FODMAP dosages used were chosen to reflect realistic quantities consumed in a UK diet. Participants were instructed to follow a low FODMAP diet throughout the trial. Gastrointestinal symptoms and stool output were recorded by participants the day before each challenge and daily during the 3-day challenge, using the validated Gastrointestinal Symptom Rating Scale (GSRS) and Bristol Stool Form Scale, respectively. Adequate symptom relief was assessed by using the global symptom question.
Data for 29 participants who completed all arms was analysed (12 CD; 17 UC). Participants were aged 22-69 years, 18 were female. All participants reported high adherence to the low FODMAP diet during all of the challenges. Significantly fewer participants reported adequate relief of the final day of fructan challenge (62.1%) than the glucose placebo challenge (89.7%), p=0.033. No significant differences were found between GOS or sorbitol compared to glucose. Participants also recorded significantly greater number of days of moderate or severe pain (p=0.014), bloating (p=0.017) and flatulence (p=0.034) during the fructan challenge compared to glucose placebo only. Furthermore, participants reported significantly greater severity of pain (p=0.004), bloating (p=0.002), flatulence (p=0.004) and faecal urgency (p=0.014) on the final day of fructan challenge compared to glucose placebo. A significantly greater composite symptom score on the final day of fructan challenge compared to glucose was also noted (p=0.002). There was no significant difference in any of the individual scores or in the composite score on the final day or all three days of the GOS or sorbitol challenges compared to glucose placebo. The lack of symptom exacerbation following GOS and sorbitol may be due to the fact that doses were inadequate to generate symptoms, additionally, it could be that FODMAPs have an additive effect (as has been demonstrated in IBS trials), hence when several FODMAPs are combined within foods and administered throughout the day, a significant worsening of symptoms may occur.
This re-challenge trial identified that fructans, but not GOS and sorbitol (at the doses given) induced gastrointestinal symptoms in patients with quiescent IBD. Further investigation will be required to establish the effects of different types and doses of FODMAPs on FGS in patients with IBD, and the effect of a low FODMAP diet and the degree of FODMAP restriction required for gastrointestinal symptoms improvement in patients with quiescent IBD.
Link to original study
The aim of this study was to conduct a randomized, double-blinded, placebo-controlled, cross-over, re-challenge trial, designed to compare the effects of FODMAP challenges to a placebo (glucose) on FGS in patients with quiescent IBD, experiencing co-existent FGS.
Participants were recruited from gastroenterology clinics at Guy’s and St Thomas’ and Bart’s Hospitals. The inclusion criteria were a diagnosis of Crohn’s disease (CD) or ulcerative colitis (UC) at least 6 months prior to involvement and currently in remission. In addition, participants must have been experiencing FGS that met Rome III criteria for IBS and experienced a marked improvement following a low FODMAP diet. Eligible participants were allocated to a series of 4 FODMAP challenges in random order, each with a duration of 3 days and separated by a washout period of at least 4 days. The four challenges were: 12g/day of fructans; 6g/day GOS; 6g/day sorbitol and 12g/ day glucose (placebo). All challenges were taken as drinks and consumed once daily for 3 days. The FODMAP dosages used were chosen to reflect realistic quantities consumed in a UK diet. Participants were instructed to follow a low FODMAP diet throughout the trial. Gastrointestinal symptoms and stool output were recorded by participants the day before each challenge and daily during the 3-day challenge, using the validated Gastrointestinal Symptom Rating Scale (GSRS) and Bristol Stool Form Scale, respectively. Adequate symptom relief was assessed by using the global symptom question.
Data for 29 participants who completed all arms was analysed (12 CD; 17 UC). Participants were aged 22-69 years, 18 were female. All participants reported high adherence to the low FODMAP diet during all of the challenges. Significantly fewer participants reported adequate relief of the final day of fructan challenge (62.1%) than the glucose placebo challenge (89.7%), p=0.033. No significant differences were found between GOS or sorbitol compared to glucose. Participants also recorded significantly greater number of days of moderate or severe pain (p=0.014), bloating (p=0.017) and flatulence (p=0.034) during the fructan challenge compared to glucose placebo only. Furthermore, participants reported significantly greater severity of pain (p=0.004), bloating (p=0.002), flatulence (p=0.004) and faecal urgency (p=0.014) on the final day of fructan challenge compared to glucose placebo. A significantly greater composite symptom score on the final day of fructan challenge compared to glucose was also noted (p=0.002). There was no significant difference in any of the individual scores or in the composite score on the final day or all three days of the GOS or sorbitol challenges compared to glucose placebo. The lack of symptom exacerbation following GOS and sorbitol may be due to the fact that doses were inadequate to generate symptoms, additionally, it could be that FODMAPs have an additive effect (as has been demonstrated in IBS trials), hence when several FODMAPs are combined within foods and administered throughout the day, a significant worsening of symptoms may occur.
This re-challenge trial identified that fructans, but not GOS and sorbitol (at the doses given) induced gastrointestinal symptoms in patients with quiescent IBD. Further investigation will be required to establish the effects of different types and doses of FODMAPs on FGS in patients with IBD, and the effect of a low FODMAP diet and the degree of FODMAP restriction required for gastrointestinal symptoms improvement in patients with quiescent IBD.
Link to original study
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