Fructans and FODMAPs in Children with Irritable Bowel Syndrome

A recent randomized control trial (BP Chumpitazi et al. Clin Gastroenterol Hepatol 2018; 16: 219-25) evaluated 23 children in a double-blind placebo (maltodextrin) cross-over design (2014-2016) to determine whether fructans (0.5 g/kg/day with max 19 g divided over 3 meals) worsen symptoms in children with irritable bowel syndrome (IBS). Fructans are a commonly ingested FODMAP carbohydrate (oligosaccharides).  All subjects were 7-18 years (median 12.4 years) and met Rome III IBS criteria.

Key findings:

  • Subjects had more episodes of abdominal pain/day while receiving fructan-containing diet (3.4 ± 2.6) compared with placebo-group (2.4 ± 1.7) (P<.01).
  • The fructan group had more severe bloating (P<.05) and flatulence (P=.01).  This was associated with higher hydrogen production (617 ppm/h compared with 136 pph/h) (P<.001)
  • 18/23 (78%) had more frequent abdominal pain with fructan-containing diet and 12 (52%) had fructan sensitivity which the authors defined as having an increase of ≥30% in abdominal pain frequency following fructan ingestion.

My take: While the number of participants in this study is limited, the implications are clear: in children with irritable bowel, fructans frequently exacerbate symptoms. At this time, though, it is not possible to predict which patients with IBS will benefit.

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Chattahoochee River

Newest FODMAPs Study for IBS

From AGA twitter feed: http://t.co/vFwhS5YEF4 -Full text article.

From Abstract:

Methods

In a study of 30 patients with IBS and 8 healthy individuals (controls, matched for demographics and diet), we collected dietary data from subjects for 1 habitual week. Participants then randomly were assigned to groups that received 21 days of either a diet low in FODMAPs or a typical Australian diet, followed by a washout period of at least 21 days, before crossing over to the alternate diet. Daily symptoms were rated using a 0- to 100-mm visual analogue scale. Almost all food was provided during the interventional diet periods, with a goal of less than 0.5 g intake of FODMAPs per meal for the low-FODMAP diet. All stools were collected from days 17–21 and assessed for frequency, weight, water content, and King’s Stool Chart rating.

Results

Subjects with IBS had lower overall gastrointestinal symptom scores (22.8; 95% confidence interval, 16.7–28.8 mm) while on a diet low in FODMAPs, compared with the Australian diet (44.9; 95% confidence interval, 36.6–53.1 mm; P < .001) and the subjects’ habitual diet. Bloating, pain, and passage of wind also were reduced while IBS patients were on the low-FODMAP diet. Symptoms were minimal and unaltered by either diet among controls. Patients of all IBS subtypes had greater satisfaction with stool consistency while on the low-FODMAP diet, but diarrhea-predominant IBS was the only subtype with altered fecal frequency and King’s Stool Chart scores.

Conclusions

In a controlled, cross-over study of patients with IBS, a diet low in FODMAPs effectively reduced functional gastrointestinal symptoms. This high-quality evidence supports its use as a first-line therapy.

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An Unexpected Twist for “Gluten Sensitivity”

While the concept of gluten sensitivity without celiac disease has been recognized since 1980 (Gastroenterol 1980; 79: 801-06), a recent study indicates that gluten may not be the main culprit in inducing these symptoms (Gastroenterol 2013; 145: 320-28; editorial 276-79).

The authors of this double-blind crossover study were the same investigators who popularized the concept of nonceliac gluten sensitivity (NCGS) two years ago (Am J Gastroenterol 2011; 106: 508-14).  In this current study, they demonstrate that in NCGS patients consuming a low FODMAPs diet (see previous post links below) gluten reintroduction did not cause specific or reproducible symptoms.

Methods: In this study, they enrolled 37 subjects with NCGS who fulfilled Rome III criteria for IBS and improved on a gluten-free diet (GFD).  All participants continued their GFD and after a 1-week baseline, started on a low FODMAP diet for a 2-week run in period.  Subsequently, patients were randomly assigned to 3 study arms: high gluten (16 g gluten/day), low gluten (2 g gluten & 14 g whey per day) or control (16 g whey/day).  Each participant took this diet for 1 week, had a 2-week washout, then crossed over to each arm.  In addition, at least 8 months, 22 subjects underwent another brief crossover study (high-gluten, whey only, or control with no additional protein).  As part of the study, clinical, serological, and immunologic parameters were monitored during all aspects of the rechallenges.

Results: “Gastrointestinal symptoms consistently and significantly improved during reduced FODMAP intake, but significantly worsened to a similar degree when their diets included gluten or whey protein.” There were no changes in any serological or immunologic parameters between the dietary challenges.

There were several limitations to this study of this highly-selected cohort which are well-described in their discussion.

Bottom-line: Gluten might not be a specific trigger once dietary FODMAPs are reduced.

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Food choices, FODMAPs, and gluten haters

Given the frequency of functional gastrointestinal diseases (FGID), including irritable bowel syndrome (IBS), dietary treatments that may improve symptoms receive a lot of attention.  A recent review of the role of food choices in the development and management of FGIDs is a useful reference (Am J Gastroenterol 2012; 107: 657-66 -thanks to Ben Gold for forwarding this article).

This review details specific dietary advice as well as the following specific physiologic effects of FODMAPs:

  • Osmotic effects
  • Bacterial fermentation
  • Motility effects
  • Prebiotic effects
  • Systemic effects –mild depression, tiredness
In addition, the review looks at other potential foods which could serve as a trigger for IBS symptoms, like gluten & summarizes why some IBS patients are gluten haters.  The authors acknowledge that gluten sensitivity, in the absence of celiac disease, does not have a known mechanism.  Until a reliable marker becomes available, the importance of gluten sensitivity for FGIDs is unknown.
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What to make of FODMAPs

Gluten sensitivity without celiac disease

Is a biopsy necessary in Celiac disease?