Effects of a Very Low Carbohydrate Diet on Symptoms of Irritable Bowel Syndrome (IBS)
The purposes of this study are to prospectively determine the effect of a very low carbohydrate diet on quality of life and gastrointestinal symptoms in patients with diarrhea-predominant irritable bowel syndrome (IBS-D); and to determine possible physiological correlates of symptom improvement, as related to post-prandial 5-hydroxytryptamine (5-HT) release, weight loss and fiber content.
Diarrhea Predominant Irritable Bowel Syndrome
Other: Very low carbohydrate diet
|Study Design:||Endpoint Classification: Efficacy Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||The Effect of a Very Low Carbohydrate Diet on Symptoms of Irritable Bowel Syndrome: A Prospective Pilot Study|
- Number of Subjects Reporting "Adequate Relief" From IBS Symptoms for the Previous Week. Adequate Relief Was a "True/False" Item. [ Time Frame: At the end of each of 6 study weeks ] [ Designated as safety issue: No ]
Adequate relief was measured as the primary endpoint via a single item Adequate Relief Question asking "Over the past week have you had adequate relief of your symptom experience". Higher scores represent greater levels of adequate relief over the week prior to the assessment. Participants completed this 1-item questionnaire at the end of each of weeks of the study, assessing whether they had adequate relief of their IBS symptoms for the week.
A responder was defined as reporting adequate relief in at least 2 of the 4 weeks on the VLCD.
- Impact of Very Low Carbohydrate Diet on Stool Frequency [ Time Frame: 6 Weeks ] [ Designated as safety issue: No ]Stool Frequency was measured as number of stools per day
- Sickness Impact Profile [ Time Frame: At the end of four week VLCD ] [ Designated as safety issue: No ]Units of measurement on the Sickness Impact Profile were ordinal rated scored. Information on scoring use and interpretation of the Sickness Impact Profile, readers are encouraged to read Bergner et. al. 1981 - Bergner, M., Bobbit, R.A., Carter, W.B. et all (1981) the Sickness Impact Profile: Development and final revision of a health status measure. Medical Care, 19:787-805 The SIP measures sickness-related dysfunction based on behavior in order to provide a measure of health status that will aid in assessing the outcome of health care services.
|Study Start Date:||August 2009|
|Study Completion Date:||May 2010|
|Primary Completion Date:||May 2010 (Final data collection date for primary outcome measure)|
Other: Very low carbohydrate diet
4 weeks on strictly controlled low carbohydrate diet
Approximately 10-15% of individuals in the United States have symptoms consistent with irritable bowel syndrome (IBS) which is a costly disorder and negatively impacts patient quality of life. The pathogenesis of this heterogeneous disorder is still not well understood. Patients frequently identify worsening of symptoms after meals and often cite particular foods as triggers of their IBS symptoms. Unfortunately, there is insufficient randomized clinical trial data to allow for specific dietary recommendations. Previous research has suggested a role for carbohydrate ingestion in IBS. There is also evidence for the role of the post-prandial release of 5-hydroxytryptamine (5-HT) and its turnover (as represented by the ratio of its metabolite, 5-hydroxyindoleacetic acid (5-HIAA), to 5-HT in response to a carbohydrate-rich meal, especially in those with IBS-D. As the prevalence of overweight (body mass index [BMI] > 25 kg/m2) and obesity (BMI > 30 kg/m2) has risen in recent years, very low carbohydrate diets have become popular for those attempting to lose weight. Patients with IBS, especially IBS-D, anecdotally report improvement in their gastrointestinal symptoms after initiating a very low carbohydrate diet. However, no study has investigated the effect of a very low carbohydrate diet on symptoms and quality of life in patients with IBS-D.
|United States, North Carolina|
|UNC Center for Functional GI & Motility Disorders|
|Chapel Hill, North Carolina, United States, 27599|
|Principal Investigator:||Douglas Drossman, MD||UNC Chapel Hill|