Dietary interventions in irritable bowel syndrome

The impact of dietary interventions for irritable bowel syndrome on luminal microbiota, symptoms, nutrient intake and quality of life: a randomised controlled trial

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

ISRCTN

Registry ID

ISRCTN16562415

Enrollment

Registered

2015-03-23

Start date

2015-05-04

Completion date

Unknown

Last updated

2025-04-21

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Irritable bowel syndrome Digestive System

Interventions

1. 4 week sham diet + placebo 2. 4 week treatment diet + placebo 3. 4 week treatment diet + prebiotic

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1. Men and women aged 18-65 years with diarrhoea-predominant IBS (IBS-D), mixed-type IBS (IBS-M) or unsubtyped IBS (IBS-U) based on Rome III criteria who do not have a major medical condition (diabetes, psychiatric or current eating disorders), gastrointestinal disease (e.g. inflammatory bowel disease, coeliac disease) or history of previous GI surgery, except cholecystectomy and haemorrhoidectomy 2. Individuals able to give informed consent 3. Individuals naive to the dietary intervention

Exclusion criteria

Exclusion criteria: 1. Females who report to be pregnant or lactating 2. Consumption of antibiotics, prebiotics or probiotics (in food products or as supplements) in the last 4 weeks prior to, or during the study 3. Use of unpermitted medications 4. Participants who have received bowel preparation for investigative procedures in the 4 weeks prior to the study 5. Participants who have had changes to IBS medications or dose in the 4 weeks prior to the study 6. Less than 2 days of at least moderate abdominal pain or discomfort in the screening week 7. Individuals with additional specific dietary needs 8. Individuals with excess alcohol or caffeine intake as assessed by diet questionnaires as these substances may confound symptom results

Design outcomes

Primary

Measure	Time frame
1. Luminal bifidobacteria concentration between groups at 4 weeks 2. Adequate symptom relief between groups at 4 weeks	—

Secondary

Measure	Time frame
1. Difference in IBS symptoms between the three groups at 4-weeks. 2. Difference in stool consistency and stool frequency between three groups at 4-weeks 3. Difference in total and individual luminal gastrointestinal microbiota between the three groups at 4-weeks 4. Difference in faecal short chain fatty acids and pH between the three groups at 4-weeks 5. Differences in urine metabolomics between the three groups at 4-weeks 6. Difference in nutrient intake between dietary interventions at 4-weeks 7. Difference in QOL scores between the three groups at 4-weeks 8. Patient acceptability of the diet and food supplement (questionnaire)	—

Measure

Time frame

1. Difference in IBS symptoms between the three groups at 4-weeks. 2. Difference in stool consistency and stool frequency between three groups at 4-weeks 3. Difference in total and individual luminal gastrointestinal microbiota between the three groups at 4-weeks 4. Difference in faecal short chain fatty acids and pH between the three groups at 4-weeks 5. Differences in urine metabolomics between the three groups at 4-weeks 6. Difference in nutrient intake between dietary interventions at 4-weeks 7. Difference in QOL scores between the three groups at 4-weeks 8. Patient acceptability of the diet and food supplement (questionnaire)

—

Countries

England, United Kingdom

Contacts

Public ContactBridgette Wilson

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 4, 2026