Effects of a Very Low Carbohydrate Diet on Symptoms of Irritable Bowel Syndrome (IBS)

Diarrhea Predominant Irritable Bowel Syndrome Clinical Trial

Official title:

The Effect of a Very Low Carbohydrate Diet on Symptoms of Irritable Bowel Syndrome: A Prospective Pilot Study

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00616200
• Other study ID #: 05-2899
• Secondary ID: GCRC 2392
• Status: Completed
• Phase: N/A
• First received: February 5, 2008
• Last updated: September 13, 2017
• Start date: August 2009
• Est. completion date: May 2010

Study information

• Verified date: October 2011
• Source: University of North Carolina, Chapel Hill
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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.

Description:

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 17
• Est. completion date: May 2010
• Est. primary completion date: May 2010
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 70 Years

Eligibility

Inclusion Criteria:

1. Age 18-70 years old, male or female

2. Meet Rome II Criteria for IBS-D

3. Body mass index > 25 kg/m^2

4. Desire to use a very low carbohydrate diet for weight loss

5. Score of > 36 on the FBDSI

6. Ability to understand consent form

7. In stable health by screening history, physical examination performed by a study physician, laboratory tests (normal blood counts, kidney function tests, liver tests, TSH).

Exclusion Criteria:

1. Age < 18 years or age > 70 years

2. History of inflammatory bowel disease

3. History of any gastrointestinal surgery that preceded the onset of IBS symptoms

4. Pregnancy or breastfeeding

5. FBDSI symptom score of = 36

6. Inability to understand consent form

7. Diabetes requiring medications (must be controlled with diet and exercise alone).

8. Chronic narcotic use for any reason

9. Use of serotonin-selective reuptake inhibitors unless patient has been on a stable dose for at least 4 weeks.

10. Use of any over-the-counter or prescription weight loss medications.

11. Any chronic or unstable diseases (e.g., kidney disease, heart disease, or cancer) that may put the subject at increased risk from the intervention

12. Any of the following baseline abnormalities of laboratory tests or physical exam findings:

1. Serum creatinine > 1.5 mg/dL in men, > 1.3 mg/dL in women.

2. Liver disease (AST or ALT > 2 times the upper limit of normal or total bilirubin > 1.6mg/dL).

3. Blood pressure > 160/100 mm Hg.

4. Fasting triglycerides > 600 mg/dL.

5. Fasting serum low-density lipoprotein (LDL) cholesterol > 190 mg/dL.

Related Conditions & MeSH terms

• Diarrhea
• Diarrhea Predominant Irritable Bowel Syndrome
• Irritable Bowel Syndrome
• Syndrome

Intervention

Other:
• Very low carbohydrate diet
4 weeks on strictly controlled low carbohydrate diet

Locations

Country	Name	City	State
United States	UNC Center for Functional GI & Motility Disorders	Chapel Hill	North Carolina

Sponsors (1)

Lead Sponsor	Collaborator
University of North Carolina, Chapel Hill

Country where clinical trial is conducted

United States, 

References & Publications (1)

Austin GL, Dalton CB, Hu Y, Morris CB, Hankins J, Weinland SR, Westman EC, Yancy WS Jr, Drossman DA. A very low-carbohydrate diet improves symptoms and quality of life in diarrhea-predominant irritable bowel syndrome. Clin Gastroenterol Hepatol. 2009 Jun; — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Number of Subjects Reporting "Adequate Relief" From IBS Symptoms for the Previous Week. Adequate Relief Was a "True/False" Item.	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.	At the end of each of 6 study weeks
Secondary	Impact of Very Low Carbohydrate Diet on Stool Frequency	Stool Frequency was measured as number of stools per day	6 Weeks
Secondary	Sickness Impact Profile	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.	At the end of four week VLCD