FODMAP Reintroduction in Irritable Bowel Syndrome
FODMAP Reintroduction in Irritable Bowel Syndrome
The purpose of this study is to determine the amount and timing of when certain Fermentable
 Oligo-Di-Monosaccharides and Polyols (FODMAPs), specifically fructose, can be safely
 reintroduced into the diet of Irritable Bowel Syndrome (IBS) patients that have successfully
 completed a low-FODMAP elimination diet. The FODMAP diet is an effective treatment for IBS;
 however it is unclear how patients can successfully reintroduce and liberalize fructose into
 their diet. The low FODMAP diet is thought to reduce IBS symptoms by decreasing water content
 and gas production in the bowel and also possibly by altering gut bacteria. Although use of
 the FODMAP elimination diet can initially successfully treat IBS symptoms for up to 50-75% of
 patients, the reintroduction diet is difficult for patients to complete and maintain for long
 periods of time because current methods for reintroduction of FODMAPs are imprecise leading
 to frequent recurrent symptoms. As a result, patients often continue the low FODMAP
 elimination diet for additional months because they have difficulties knowing how to add back
 FODMAPs into their diet. There are no studies to date to help guide patients with FODMAP
 reintroduction.
Research supports clinical experience that ingestion of food often triggers the emergence or
 exacerbation of symptoms in the majority of patients with irritable bowel syndrome (IBS).
 While IBS remains primarily a symptom driven entity, our understanding of its pathophysiology
 is evolving. However, comparatively little research has focused on the specific role of
 certain foods and how they prompt the development of IBS symptoms.

 Food may be linked to changes in motility, visceral sensation, gut microbiome, intestinal
 permeability, immune activation and brain-gut axis. This study will focus on fructose, which
 is one of the main components of FODMAP (fermentable oligosaccharides, disacharides,
 mono-saccharides and polyols) foods. Fructose is a common part of the Western diet and can be
 consumed as a free monosaccharide, part of sucrose, or in polymers referred to as fructans.
 There are no human gut specific fructose transporters. Rather glucose transporters are used
 (GLUT 2,5) leading some to hypothesize that over ingestion of these agents may trigger some
 of the enteric complaints of patients with IBS. The literature on fructose malabsorption
 gives varying threshold amounts: from 15 to 50 grams in healthy controls, and from 5 to 50
 grams in IBS patients/known malabsorbers (Barrett, 2007; Rao, 2007; Frieling, 2011). Average
 daily fructose consumption in the American diet is approximately 34 grams, with a range of 15
 to 54 grams, which falls well within the threshold levels (Frieling, 2011). FODMAP foods are
 thought to induce gastrointestinal symptoms including gas, bloating, abdominal pain or
 discomfort, and loose stools by increasing small bowel water content and increasing gas
 production by fermentation of foods by gut bacteria. Studies including a recent controlled
 clinical trial demonstrated that a low FODMAP diet can be an effective nutritional therapy.

 There are risks to prolonged use of a low FODMAPs diet. A study from 2012 suggested that
 continued restriction of FODMAPS (longer than 4 weeks) can lead to reduction of luminal
 bifidobacteria in patients with IBS. Bifidobacteria mainly inhabit the large intestine where
 they produce short chain fatty acids (SCFA) as byproducts, including butyrate, shown to be
 important for colorectal cancer prevention and limit enteropathogenic colonization.
 Furthermore the diet is very restrictive and difficult for patients to maintain over time.

 However, important clinical questions include when FODMAPS can be safely reintroduced into
 the diet, how quickly this can be accomplished, and what is a daily threshold of intake that
 is acceptable for IBS patients who respond or do not respond to a low FODMAPs diet. There are
 no evidence based answers to these questions, and it is in this setting that we propose our
 current project.
Inclusion Criteria:

 -  Adults (18+ years or older) with a diagnosis of IBS-D or IBS-M based on Rome IV
 criteria

 -  Diarrhea must occur 2 or more days per week

 -  Patients on current pharmacological therapy for their gastrointestinal complaints can
 enroll in the study as long as they have been on a stable dose for at least 30 days.

 Exclusion Criteria:

 -  Significant comorbidities that are associated with GI symptoms (e.g. diabetes,
 scleroderma, SLE), history of GI surgery excluding appendectomy, or prior organic GI
 illness

 -  Antibiotics taken in the past 2 months

 -  Current disordered eating patterns (diagnosed eating disorder; as per verbal ESP
 questionnaire)

 -  Current history of greater than moderate alcohol intake (more than 1 drink per day for
 women, more than 2 drinks per day for men, binge drinking behavior of 5+ drinks in a
 single session once per week)

 -  Cannot have had a cholecystectomy in the past 6 months prior to enrollment