Actively Recruiting
Irritable Bowel Syndrome and Control Volunteers: Diet Challenge
Led by University of California, Los Angeles · Updated on 2025-12-09
72
Participants Needed
1
Research Sites
317 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
The study will investigate the relationship between fecal bile acids, short-chain fatty acids (SCFAs), and the gut microbiota in irritable bowel syndrome (IBS). The central hypothesis of this study is that specific shifts in the GI microbiome composition correlate with altered colonic SCFAs and BAs and contribute to IBS symptoms. Primary aims include: (a) identifying GI microbiome signatures in IBS subtypes (IBS-C and IBS-D) and matched controls, and test if microbiome signatures in these groups correlate with fecal SCFAs and bacterial fermentation of an indigestible carbohydrate (inulin) after a dietary challenge (fecal inulin), and (b) determining if GI microbiome signatures in IBS subtypes and controls correlate with fecal BAs or markers of SCFA production (fecal SCFAs or inulin) and test if BAs correlate with fecal SCFAs or inulin. The target population is adults ages 18-65 years meeting Rome IV criteria for IBS (both diarrhea- and constipation-predominant, IBS-D and IBS-C) and asymptomatic controls. Primary outcomes will be fecal bile acid excretion and profile, short-chain fatty acid excretion and profile, colonic transit, and fecal microbiota. Secondary outcomes will be stool characteristics based on responses to validated bowel diaries. Stool samples will be collected from participants during the last 2 days of a 4-day 100 g fat diet and split into 3 samples for fecal microbiota, SCFA, and bile acid analysis.
CONDITIONS
Official Title
Irritable Bowel Syndrome and Control Volunteers: Diet Challenge
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Age 18-75
- Individuals with irritable bowel syndrome (IBS)
- Healthy volunteers with no prior history of gastrointestinal (GI) disease or symptoms
- No dietary restrictions other than vegetarian
You will not qualify if you...
- Inflammatory bowel disease, celiac disease, or certain types of abdominal cancer
- Thyroid or liver issues
- Abdominal surgery or abdominal radiation within 6 months (except C-section or gallbladder removal)
- Use of medications affecting gastrointestinal function within 6 months (healthy volunteers) or 2 days (IBS participants), except stable low-dose antidepressants used for over one month
- Use of rescue medication like Bisacodyl only if needed
- Use of Ozempic or similar medications
- Pregnant or breastfeeding women
- Antibiotic use within 3 months
- Use of prebiotics or probiotics within 2 weeks before study
- Regular tobacco use within the past 6 months
AI-Screening
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Trial Site Locations
Total: 1 location
1
University of California, Los Angeles
Los Angeles, California, United States, 90095
Actively Recruiting
How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
NON_RANDOMIZED
Model
SINGLE_GROUP
Primary Purpose
DIAGNOSTIC
Number of Arms
3
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