An interventional study of Dietary Intervention in Irritable Bowel Syndrome With Diarrhea and Irritable Bowel Syndrome With Mixed Bowel Habits, sponsored by University of California, Los Angeles. Completed at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2023-07-11.
Sponsored by University of California, Los Angeles · Not applicable, Interventional, and Treatment
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.
1,062 studies on the registry are indexed under Irritable Bowel Syndrome; 190 are open to participants now.
This study's enrollment of 30 is below the median of 71 across 853 interventional studies indexed under Irritable Bowel Syndrome.
Browse Irritable Bowel Syndrome studies →University of California, Los Angeles is the lead sponsor of 1,142 studies on the registry; 192 are open to participants now.
Of its 91 completed or terminated interventional studies of FDA-regulated products, 66 (73%) have results posted.
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Exclusion Criteria:
The fructose group will help to determine whether an absolute amount of fructose will lead to IBS symptoms.
Other: Dietary Intervention
The glucose group will serve as a control since glucose is not a FODMAP and as a result is not expected to lead to recurrent symptoms.
Other: Dietary Intervention
The glucose/fructose mixture group is a cross comparison group that will determine whether the relative excess fructose concentration is an important cause of IBS symptoms.
Other: Dietary Intervention
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, dissacharides, 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. 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.
Adequate relief of IBS symptoms in past 7 days
As indicated by the study coordinator asking the participant "Have you had adequate relief of your IBS symptoms in the past 7 days?"
Time frame: Baseline, 4 weeks (post-elimination diet)
Highest amount of grams of sugar in solutions that do not significantly increase IBS symptoms
As measured by 100 MM Visual Analog Scale (VAS) with 0 representing no symptoms for overall gastrointestinal symptoms.
Time frame: Daily, during weeks 5-7 (reintroduction phase)
Change in IBS-symptom severity scale
This is a validated symptom questionnaire pertaining to irritable bowel syndrome symptoms
Time frame: Baseline, 4 weeks (post-elimination diet), 7 weeks (post-reintroduction phase)
Change in Visceral Sensitivity Index (VSI)
This is a self-report measure of the gastrointestinal symptom-specific anxiety (GSA) of patients with irritable bowel syndrome (IBS)
Time frame: Baseline, 4 weeks (post-elimination diet), 7 weeks (post-reintroduction phase)
Change in Personal Health Questionnaire (PHQ-15)
This is a validated symptom questionnaire pertaining to somatic symptoms severity
Time frame: Baseline, 4 weeks (post-elimination diet), 7 weeks (post-reintroduction phase)
Change in abdominal pain severity
This is a self-report measure of the severity of abdominal pain during the week before report gathered by circling a number from 0-20 with 20 being the most intense pain imaginable.
Time frame: Baseline, 4 weeks (post-elimination diet), 7 weeks (post-reintroduction phase)
Change in overall severity of gastrointestinal symptoms
This is a self-report measure of the overall severity of gastrointestinal symptoms during the week before report gathered by circling a number from 0-20 with 20 being the most intense symptoms imaginable.
Time frame: Baseline, 4 weeks (post-elimination diet), 7 weeks (post-reintroduction phase)
Change in severity of the sensation of bloating, abdominal fullness or visible distension
This is a self-report measure of the severity of the sensation of bloating, abdominal fullness, or visible distension in the patient's belly that the patient has experienced during the week before report gathered by circling a number from 0-20 with 20 being the most intense sensation imaginable.
Time frame: Baseline, 4 weeks (post-elimination diet), 7 weeks (post-reintroduction phase)
Change in intestinal microbiota
This is a measure of the intestinal microbiota 16S rRNA gene signatures in the patients' stool before and after the low FODMAP diet.
Time frame: Baseline, 4 weeks (post-elimination diet)
Change in visceral sensitivity index score
This is a validated symptom questionnaire pertaining to gastrointestinal symptom related anxiety in patients with irritable bowel syndrome.
Time frame: Baseline, 4 weeks (post-elimination diet), 7 weeks (post-reintroduction phase)
This study is completed, as verified in Jul 2023. You cannot join it, but the record below documents what was studied.
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University of California, Los Angeles