CARIBS: A Comparison of Three Different Treatment Options for Irritable Bowel Syndrome

Sponsor

Sahlgrenska University Hospital, Sweden (Other)

Overall Status

Recruiting

CT.gov ID

NCT02970591

Collaborator

(none)

300

Enrollment

Location

Arms

Duration (Months)

4.6

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

Irritable Bowel Syndrome is a common disease to which there is no curable treatment. Diet is considered to trigger symptoms associated with the clinical picture of IBS, and dietary treatment is thus believed to relieve the symptoms of IBS. As the disease is very heterogeneous in its manifestation, different treatment options might be indicated depending on the predominant symptom. To investigate the response to different dietary treatment options, a randomized controlled intervention trial will be carried out in adult patients (>18 y) with IBS according to Rome III criteria. The aim of this study is to compare the response to two different dietary treatments or optimized medical treatment.

Condition or Disease	Intervention/Treatment	Phase
Irritable Bowel Syndrome	Other: Traditional dietary advice and low FODMAP content Other: Low carbohydrate diet Other: Optimized Medical treatment	N/A

Detailed Description

The study is a randomized controlled trial comparing three different treatments during four weeks:

Combination of low FODMAP diet + traditional dietary advice (based on NICE recommendations)

Eat at regular hours; 3 main meals and 3 snacks
Eat in peace, chew the food properly
Peel all fruits and vegetables
Limit intake of spicy and fatty foods, coffe, alcohol, avoid fizzy drinks and chewing gum
Choose soluble rather than insoluble fibres
Avoid foods high in FODMAPs

Diet low in carbohydrates

10 E% carbohydrates, 25 E% protein, 65 E% fat
Larger amounts of fish, shellfish, meat, egg, dairy products (lactose free if wanted) nuts, seeds, oil, vegetables
No sugary or starchy foods, e.g pasta, potatoes, bread, rice, most fruits
No specific consideration about FODMAP content

Optimized pharmacological tretament based on predominant symptom and previous experience with pharmacological treatmment.

Pain/discomfort:

Pain: Amitriptyline 25 mg. Increase to 50 mg if needed
Episodic pain: Hyoscyamine 0,2mg 2x2; adjust dose if needed
Pain with diarrhea: Amitriptyline 25 mg. Increase dose if needed
Pain with constipation: Linaclotide 290 microgram 1x1

Constipation:

Bulking agent (Sterculia gum (Inolaxol) 1x1. Increase to 1x3 if needed
Osmotic laxative (Macrogol (Movicol) 1x1
Linaclotide 290 microgram 1x1 Diarrhea
Loperamide 1x2 . Adjust dose if needed
Cholestyramine 1x1. Increase ever 3-5 d as needed
Ondansetron 4mg 1x1. Increase to 1x2-3 if needed
Eluxadoline 100mg 1x2

Primary endpoint: IBS-SSS reduction >50 points

Study Design

Study Type:

Interventional

Anticipated Enrollment :

300 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

Single (Outcomes Assessor)

Primary Purpose:

Supportive Care

Official Title:

The Role of CARbohydrates in Irritable Bowel Syndrome (CARIBS): Protocol for a Randomized Controlled Trial Comparing Three Different Treatment Options

Study Start Date :

Jan 1, 2017

Anticipated Primary Completion Date :

Dec 1, 2021

Anticipated Study Completion Date :

Jun 1, 2022

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Diet B Low carbohydrate diet	Other: Low carbohydrate diet Diet that contains a maximum of 10 energy percent of carbohydrates, 25 energy % proteins and 65 energy % fat.
Active Comparator: Medical treatment Optimized Medical treatment	Other: Optimized Medical treatment Standard consultation by physician and if needed patients will receive medical treatment based on the most prominent symptom. Constipation: osmotic laxatives, linaclotide. Diarrhea: loperamid, bile acid binders. Pain: anti depressent, antispasmodics, linaclotide.
Experimental: Diet A Traditional dietary advice and low FODMAP content	Other: Traditional dietary advice and low FODMAP content Traditional dietary advice according to the Brittish Dietetic Association including reducing the intake of fermentable carbohydrates.

Arm

Intervention/Treatment

Experimental: Diet B

Low carbohydrate diet

Other: Low carbohydrate diet

Diet that contains a maximum of 10 energy percent of carbohydrates, 25 energy % proteins and 65 energy % fat.

Active Comparator: Medical treatment

Optimized Medical treatment

Other: Optimized Medical treatment

Standard consultation by physician and if needed patients will receive medical treatment based on the most prominent symptom. Constipation: osmotic laxatives, linaclotide. Diarrhea: loperamid, bile acid binders. Pain: anti depressent, antispasmodics, linaclotide.

Experimental: Diet A

Traditional dietary advice and low FODMAP content

Other: Traditional dietary advice and low FODMAP content

Traditional dietary advice according to the Brittish Dietetic Association including reducing the intake of fermentable carbohydrates.

Outcome Measures

Primary Outcome Measures

The proportion (%) of patients who respond to treatment [Baseline to 4 weeks]
A responder is defined as having an IBS-SSS reduction >50 points @ 4 weeks

Secondary Outcome Measures

Change in symptom severity [Baseline, 4 weeks, 3 and 6 months]
Absolute and percentage change in IBS-SSS
Determinants for GI symptoms by IBS-SSS [Baseline, 4 weeks, 3 and 6 months]
GI symptoms measured by IBS-SSS
Determinants for GI symptoms by GSRS-IBS [Baseline, 4 weeks, 3 and 6 months]
GI symptoms measured by GSRS-IBS
Predictors of response to treatment [Baseline to 4 weeks]
Potential predictors include demographics, questionnaire data, microbiota, metabolites, immunology
Adherence to allocated intervention [Baseline, 4 weeks, 3 and 6 months]
Including compliance to dietary intervention during 4 weeks, and long-term adherence during follow-up
Change in microbiota content [Baseline, 4 weeks, 6 months]
Fecal microbiota analysis using 16S technique
Change in extra-intestinal symptoms and quality of life [Baseline, 4 weeks, 3 and 6 months]
As assessed by IBS specific questionnaires
Change in metabolic profile [Baseline, 4 weeks, 6 months]
Metabolomics in serum and urine samples

Other Outcome Measures

Qualitative assessment [Approx. at 3 months follow-up]
Patient's subjective experiences related to the dietary intervention described by qualitative methods.

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

IBS according to ROME III criteria, BMI 18-35, ability to communicate in Swedish, Gothenburg region resident

Exclusion Criteria:

Heart, liver, neurologic or psychiatric disease or illness
Serious gastrointestinal diseases
Celiac disease
Diabetes
Other conditions or surgery that affects the gastrointestinal function
Hyperlipidemia
Food allergy or intolerance other than lactose
Adherence to a specific diet
Being pregnant or breastfeeding
Previously been treated with any of the intervention arms, including having tested all of the pharmacological treatment options of relevance for the symptom profile of the patient