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

University of North Carolina (UNC)

Status

Completed

Conditions

Diarrhea Predominant Irritable Bowel Syndrome

Treatments

Other: Very low carbohydrate diet

Study type

Interventional

Funder types

Other

Identifiers

NCT00616200

GCRC 2392

05-2899

Details and patient eligibility

About

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.

Full 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.

Enrollment

17 patients

Sex

All

Ages

18 to 70 years old

Volunteers

No Healthy Volunteers

Inclusion criteria

Age 18-70 years old, male or female
Meet Rome II Criteria for IBS-D
Body mass index > 25 kg/m^2
Desire to use a very low carbohydrate diet for weight loss
Score of > 36 on the FBDSI
Ability to understand consent form
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

Age < 18 years or age > 70 years
History of inflammatory bowel disease
History of any gastrointestinal surgery that preceded the onset of IBS symptoms
Pregnancy or breastfeeding
FBDSI symptom score of ≤ 36
Inability to understand consent form
Diabetes requiring medications (must be controlled with diet and exercise alone).
Chronic narcotic use for any reason
Use of serotonin-selective reuptake inhibitors unless patient has been on a stable dose for at least 4 weeks.
Use of any over-the-counter or prescription weight loss medications.
Any chronic or unstable diseases (e.g., kidney disease, heart disease, or cancer) that may put the subject at increased risk from the intervention
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.