Irritable Bowel Syndrome (IBS)NCT06668922
Irritable Bowel Syndrome and Control Volunteers: Diet Challenge
A study testing Inulin in people with Irritable Bowel Syndrome (IBS), run by University of California, Los Angeles at 1 site in United States.
Trial summary
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… Read more about this study
- Who is it for?
- Ages 18 to 75 yearsHealthy volunteers can take part
- Conditions the study is for
- Irritable Bowel Syndrome (IBS)
- What is being tested?
- Inulin
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 72 participants
- Where
- 1 siteUnited States
- Study dates
- 28 Nov 2024to 31 Dec 2030
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 75 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Age 18-75
- Individuals with irritable bowel syndrome (IBS)
- Healthy volunteers (healthy controls) with no prior history of gastrointestinal (GI) disease or symptoms
- No dietary restrictions other than vegetarian
Who cannot join
- Inflammatory bowel disease, celiac disease, or certain types of abdominal cancer, as well as those with thyroid or liver issues
- Abdominal surgery or abdominal radiation within 6 months of study participation, with an exception for C-section or gallbladder removal
- Use of any prescription, over the counter, or herbal medications known to affect gastrointestinal function or study interpretation, such as opioids, inflammatory drugs or certain antidepressants, within 6 months prior to study participation for healthy volunteers, or within 2 days of study participation for participants with IBS.
- An exception will be permitted for limited use of stable low doses of antidepressants for individuals who have been taking them for a period greater than one month.
- Rescue medication such as Bisacodyl (dulcolax) to relieve severe constipation and allow for stool collection will be permitted when needed.
- Use of Ozempic and Ozempic-type medications
Show all 10Show fewer
- Pregnant or breastfeeding women
- Antibiotic use within 3 months of study participation
- Use of prebiotics or probiotics within the 2 weeks before the study initiation
- Regular tobacco use within the past 6 months
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of California, Los Angeles
Los Angeles, California, 90095
Ren Cutrer, (310) 794-9507, rcutrer@mednet.ucla.edu
Andrea S Shin
About this study
Official title: Fecal Bile Acids, Fecal Short Chain Fatty Acids and the Intestinal Microbiota in Patients With Irritable Bowel Syndrome (IBS) and Control Volunteers: Diet Challenge
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.
Read the detailed description
During the study:
Screening/Visit 1
- Participants will be asked to read and sign this informed consent after all questions about the study have been answered to satisfaction.
- This is a screening visit, and we may determine that a participant is ineligible to continue to participate in the study.
- The study team will collect medication and medical history.
- A physical exam will be performed by the physician. Vital signs and body measurements will be collected.
- Participants will be provided with a take-home lasagna meal (vegetarian and non-vegetarian option) and dessert.
- Participants will receive a stool collection kit and instructions for the collection, storage, and transportation of stool.
- Instructions will be provided for a low fiber, high fat diet for Days 2-4.
- Participants will be asked to complete diet recall using the ASA24 and a bowel pattern diary to record bowel symptoms over the course of the study.
- IBS participants will complete the irritable bowel syndrome severity scoring system questionnaires (IBS-SSS).
Day 2-4 (at home):
- Participants will record stool symptoms and patterns in a diary daily.
- Participants will be instructed to consume a low fiber diet (maximum one piece of fruit and 100 g of vegetables a day, and white flour instead of whole grain products), avoid alcohol, and start a 4-day 100 g fat diet.
- On the evening before Day 5, participants will be instructed to collect a stool sample at home and return during Visit 2.
Day 5 (Visit 2):
- Participants will return to the clinic on Day 5 after an overnight fast.
- Participants in the reproductive age range will be given a urine pregnancy test prior to inulin ingestion and the study team will confirm a negative test result.
- Participants will receive breakfast onsite. The non-vegetarian option will consist of pancakes, butter, syrup, hard-boiled eggs, and bacon. The vegetarian option will substitute the bacon with a cheese snack (approximately 790 to 840 kcal) along with 10 g inulin Orafti® powder) thoroughly mixed in 200 mL of water.
- Take-home meals will be provided for lunch and dinner and are to be consumed at 4 and 8 hours from breakfast.
- IBS participants will complete the irritable bowel syndrome severity scoring system (IBS-SSS) questionnaire.
- A stool sample will be collected on Day 5.
- Participants will continue to complete diet recall using the ASA24 and a bowel pattern diary to record bowel symptoms over the course of the study.
Day 6
- Participants will be instructed to collected a final stool sample (Day 6).
- Participants will continue to complete diet recall using the ASA24 and a bowel pattern diary to record bowel symptoms over the course of the study.
Day 7 (Visit 3)
- Participants will return to the clinic to return stool collections (Day 5 and Day 6), the daily diaries, and the IBS-SSS forms (if applicable).
Day 30-90 (Optional dietary follow-up): To further assess the utility of the 24 hour dietary recall, willing participants will be invited to participate in a an optional follow-up activity during which they will complete the Automated Self-Administered Dietary Assessment Tool with or without assistance of a trained interviewer. Interested volunteers will be contacted by phone and provided instructions on how to complete the tool online by the study team.
- Conditions
- Irritable Bowel Syndrome (IBS)
- Being tested
- Inulin
- Keywords
- irritable bowel syndrome, IBS, short-chain fatty acids, SCFAs, bile acids, fecal inulin, microbiota
- Medical subject headings
- Irritable Bowel Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
InulinDietary supplement
Inulin ingestion is not being used to diagnose, treat, or prevent IBS. Inulin is being used to study an individual's ability to ferment dietary fiber.
| Study group | Role | What they receive |
|---|---|---|
| Healthy volunteers | Experimental | Adults ages 18-65 years with no prior history of gastrointestinal diseases or symptoms. Receives: Dietary Supplement: Inulin |
| Irritable Bowel Syndrome Patients with Diarrhea (IBS-D) | Experimental | Patients with irritable bowel syndrome (IBS) with diarrhea, ages 18-65 years fulfilling Rome IV criteria for IBS. Receives: Dietary Supplement: Inulin |
| Irritable Bowel Syndrome Patients with Constipation (IBS-C) | Experimental | Patients with irritable bowel syndrome (IBS) with constipation, ages 18-65 years fulfilling Rome IV criteria for IBS. Receives: Dietary Supplement: Inulin |
What is being measured
The primary outcome is the main question the study is designed to answer.
Total fecal bile acids
Stool samples will be collected over 2 days for measurement of fecal bile acids (µmol/48h) by high performance liquid chromatography-mass spectometry.
Measured: 48 hours
Total fecal short chain fatty acids
Stool samples will be collected for measurement of measurement of short chain fatty acids (µg/mg) by liquid chromatography-mass spectrometry
Measured: 48 hours
Individual fecal short chain fatty acids
Stool samples will be collected for measurement of measurement of short chain fatty acids (µg/mg) by liquid chromatography-mass spectrometry
Measured: 48 hours
Fecal microbial population
Stool samples will be be collected from participants for nucleic acid extraction, 16S allele PCR and sequencing to measure microbial communities and profiles of specimens
Measured: 48 hours
Fecal inulin
Fecal inulin content will be measured using short acid hydrolysis and high-performance liquid chromatography
Measured: 48 hours
Secondary outcomes (2)
Percent primary fecal bile acids
Stool samples will be collected over 2 days for measurement of fecal bile acids (µmol/48h) by high performance liquid chromatography-mass spectrometry.
Measured: 48 hours
Stool characteristics
Stool characteristics will be measured using a 4 day bowel diary
Measured: 4 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Nov 2024
- Study start28 Nov 2024
- Primary completion31 Dec 2029 (estimated)
- Study completion31 Dec 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (71)Papers the sponsor has linked to this study.
- Other trials for Irritable Bowel Syndrome (IBS)Studies of the same condition, open and under way.
- More trials run by University of California, Los AngelesThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 72 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of California, Los Angeles
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Andrea S. Shin, MD, University of California, Los Angeles
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06668922
- Sponsor's protocol ID
- 24-0442
- Status last verified
- Aug 2026
- First submitted
- 30 Oct 2024
- Last updated
- 12 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Wong BS, Camilleri M, McKinzie S, Burton D, Graffner H, Zinsmeister AR. Effects of A3309, an ileal bile acid transporter inhibitor, on colonic transit and symptoms in females with functional constipation. Am J Gastroenterol. 2011 Dec;106(12):2154-64. doi: 10.1038/ajg.2011.285. Epub 2011 Aug 30.
PubMed 21876564Chey WD, Camilleri M, Chang L, Rikner L, Graffner H. A randomized placebo-controlled phase IIb trial of a3309, a bile acid transporter inhibitor, for chronic idiopathic constipation. Am J Gastroenterol. 2011 Oct;106(10):1803-12. doi: 10.1038/ajg.2011.162. Epub 2011 May 24.
PubMed 21606974Walters JR, Johnston IM, Nolan JD, Vassie C, Pruzanski ME, Shapiro DA. The response of patients with bile acid diarrhoea to the farnesoid X receptor agonist obeticholic acid. Aliment Pharmacol Ther. 2015 Jan;41(1):54-64. doi: 10.1111/apt.12999. Epub 2014 Oct 20.
PubMed 25329562Musch MW, Bookstein C, Xie Y, Sellin JH, Chang EB. SCFA increase intestinal Na absorption by induction of NHE3 in rat colon and human intestinal C2/bbe cells. Am J Physiol Gastrointest Liver Physiol. 2001 Apr;280(4):G687-93. doi: 10.1152/ajpgi.2001.280.4.G687.
PubMed 11254495Murray RD, McClung HJ, Li BU, Ailabouni A. Stimulatory effects of short-chain fatty acids on colonic absorption in newborn piglets in vivo. J Pediatr Gastroenterol Nutr. 1989 Jan;8(1):95-101. doi: 10.1097/00005176-198901000-00018.
PubMed 2732869Fukumoto S, Tatewaki M, Yamada T, Fujimiya M, Mantyh C, Voss M, Eubanks S, Harris M, Pappas TN, Takahashi T. Short-chain fatty acids stimulate colonic transit via intraluminal 5-HT release in rats. Am J Physiol Regul Integr Comp Physiol. 2003 May;284(5):R1269-76. doi: 10.1152/ajpregu.00442.2002.
PubMed 12676748Mitsui R, Ono S, Karaki S, Kuwahara A. Neural and non-neural mediation of propionate-induced contractile responses in the rat distal colon. Neurogastroenterol Motil. 2005 Aug;17(4):585-94. doi: 10.1111/j.1365-2982.2005.00669.x.
PubMed 16078948Banasiewicz T, Krokowicz L, Stojcev Z, Kaczmarek BF, Kaczmarek E, Maik J, Marciniak R, Krokowicz P, Walkowiak J, Drews M. Microencapsulated sodium butyrate reduces the frequency of abdominal pain in patients with irritable bowel syndrome. Colorectal Dis. 2013 Feb;15(2):204-9. doi: 10.1111/j.1463-1318.2012.03152.x.
PubMed 22738315Mortensen PB, Andersen JR, Arffmann S, Krag E. Short-chain fatty acids and the irritable bowel syndrome: the effect of wheat bran. Scand J Gastroenterol. 1987 Mar;22(2):185-92. doi: 10.3109/00365528708991878.
PubMed 3033815Tana C, Umesaki Y, Imaoka A, Handa T, Kanazawa M, Fukudo S. Altered profiles of intestinal microbiota and organic acids may be the origin of symptoms in irritable bowel syndrome. Neurogastroenterol Motil. 2010 May;22(5):512-9, e114-5. doi: 10.1111/j.1365-2982.2009.01427.x. Epub 2009 Nov 10.
PubMed 19903265Treem WR, Ahsan N, Kastoff G, Hyams JS. Fecal short-chain fatty acids in patients with diarrhea-predominant irritable bowel syndrome: in vitro studies of carbohydrate fermentation. J Pediatr Gastroenterol Nutr. 1996 Oct;23(3):280-6. doi: 10.1097/00005176-199610000-00013.
PubMed 8890079Aguilera M, Cerda-Cuellar M, Martinez V. Antibiotic-induced dysbiosis alters host-bacterial interactions and leads to colonic sensory and motor changes in mice. Gut Microbes. 2015;6(1):10-23. doi: 10.4161/19490976.2014.990790. Epub 2015 Jan 20.
PubMed 25531553Jalanka-Tuovinen J, Salojarvi J, Salonen A, Immonen O, Garsed K, Kelly FM, Zaitoun A, Palva A, Spiller RC, de Vos WM. Faecal microbiota composition and host-microbe cross-talk following gastroenteritis and in postinfectious irritable bowel syndrome. Gut. 2014 Nov;63(11):1737-45. doi: 10.1136/gutjnl-2013-305994. Epub 2013 Dec 5.
PubMed 24310267Lovell RM, Ford AC. Global prevalence of and risk factors for irritable bowel syndrome: a meta-analysis. Clin Gastroenterol Hepatol. 2012 Jul;10(7):712-721.e4. doi: 10.1016/j.cgh.2012.02.029. Epub 2012 Mar 15.
PubMed 22426087Simren M, Brazier J, Coremans G, Dapoigny M, Muller-Lissner SA, Pace F, Smout AJ, Stockbrugger RW, Vatn MH, Whorwell PJ. Quality of life and illness costs in irritable bowel syndrome. Digestion. 2004;69(4):254-61. doi: 10.1159/000079846. Epub 2004 Jul 14.
PubMed 15256832
Study at a glance
From the registry record, last updated by the sponsor on 12 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Fecal Bile Acids, Fecal Short Chain Fatty Acids and the Intestinal Microbiota in Patients With Irritable Bowel Syndrome (IBS) and Control Volunteers: Diet Challenge
- ClinicalTrials.gov ID
- NCT06668922
- Acronym / sponsor ID
- 24-0442
- Conditions
- Irritable Bowel Syndrome (IBS)
- Keywords
- irritable bowel syndrome, IBS, short-chain fatty acids, SCFAs, bile acids, fecal inulin, microbiota
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 72 participants (estimated)
- Lead sponsor
- University of California, Los AngelesUniversity, hospital or other
- Study start
- 28 Nov 2024 (actual)
- Primary completion
- 31 Dec 2029 (estimated)
- Study completion
- 31 Dec 2030 (estimated)
- First posted
- 1 Nov 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
During the study:
Screening/Visit 1
- Participants will be asked to read and sign this informed consent after all questions about the study have been answered to satisfaction.
- This is a screening visit, and we may determine that a participant is ineligible to continue to participate in the study.
- The study team will collect medication and medical history.
- A physical exam will be performed by the physician. Vital signs and body measurements will be collected.
- Participants will be provided with a take-home lasagna meal (vegetarian and non-vegetarian option) and dessert.
- Participants will receive a stool collection kit and instructions for the collection, storage, and transportation of stool.
- Instructions will be provided for a low fiber, high fat diet for Days 2-4.
- Participants will be asked to complete diet recall using the ASA24 and a bowel pattern diary to record bowel symptoms over the course of the study.
- IBS participants will complete the irritable bowel syndrome severity scoring system questionnaires (IBS-SSS).
Day 2-4 (at home):
- Participants will record stool symptoms and patterns in a diary daily.
- Participants will be instructed to consume a low fiber diet (maximum one piece of fruit and 100 g of vegetables a day, and white flour instead of whole grain products), avoid alcohol, and start a 4-day 100 g fat diet.
- On the evening before Day 5, participants will be instructed to collect a stool sample at home and return during Visit 2.
Day 5 (Visit 2):
- Participants will return to the clinic on Day 5 after an overnight fast.
- Participants in the reproductive age range will be given a urine pregnancy test prior to inulin ingestion and the study team will confirm a negative test result.
- Participants will receive breakfast onsite. The non-vegetarian option will consist of pancakes, butter, syrup, hard-boiled eggs, and bacon. The vegetarian option will substitute the bacon with a cheese snack (approximately 790 to 840 kcal) along with 10 g inulin Orafti® powder) thoroughly mixed in 200 mL of water.
- Take-home meals will be provided for lunch and dinner and are to be consumed at 4 and 8 hours from breakfast.
- IBS participants will complete the irritable bowel syndrome severity scoring system (IBS-SSS) questionnaire.
- A stool sample will be collected on Day 5.
- Participants will continue to complete diet recall using the ASA24 and a bowel pattern diary to record bowel symptoms over the course of the study.
Day 6
- Participants will be instructed to collected a final stool sample (Day 6).
- Participants will continue to complete diet recall using the ASA24 and a bowel pattern diary to record bowel symptoms over the course of the study.
Day 7 (Visit 3)
- Participants will return to the clinic to return stool collections (Day 5 and Day 6), the daily diaries, and the IBS-SSS forms (if applicable).
Day 30-90 (Optional dietary follow-up): To further assess the utility of the 24 hour dietary recall, willing participants will be invited to participate in a an optional follow-up activity during which they will complete the Automated Self-Administered Dietary Assessment Tool with or without assistance of a trained interviewer. Interested volunteers will be contacted by phone and provided instructions on how to complete the tool online by the study team.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Healthy volunteers | Experimental | Dietary Supplement: InulinAdults ages 18-65 years with no prior history of gastrointestinal diseases or symptoms. |
| Irritable Bowel Syndrome Patients with Diarrhea (IBS-D) | Experimental | Dietary Supplement: InulinPatients with irritable bowel syndrome (IBS) with diarrhea, ages 18-65 years fulfilling Rome IV criteria for IBS. |
| Irritable Bowel Syndrome Patients with Constipation (IBS-C) | Experimental | Dietary Supplement: InulinPatients with irritable bowel syndrome (IBS) with constipation, ages 18-65 years fulfilling Rome IV criteria for IBS. |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Age 18-75
- Individuals with irritable bowel syndrome (IBS)
- Healthy volunteers (healthy controls) with no prior history of gastrointestinal (GI) disease or symptoms
- No dietary restrictions other than vegetarian
Key exclusion criteria (10 listed)
- Inflammatory bowel disease, celiac disease, or certain types of abdominal cancer, as well as those with thyroid or liver issues
- Abdominal surgery or abdominal radiation within 6 months of study participation, with an exception for C-section or gallbladder removal
- Use of any prescription, over the counter, or herbal medications known to affect gastrointestinal function or study interpretation, such as opioids, inflammatory drugs or certain antidepressants, within 6 months prior to study participation for healthy volunteers, or within 2 days of study participation for participants with IBS.
- An exception will be permitted for limited use of stable low doses of antidepressants for individuals who have been taking them for a period greater than one month.
- Rescue medication such as Bisacodyl (dulcolax) to relieve severe constipation and allow for stool collection will be permitted when needed.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| InulinInulin ingestion is not being used to diagnose, treat, or prevent IBS. Inulin is being used to study an individual's ability to ferment dietary fiber. | Dietary supplement | Healthy volunteers, Irritable Bowel Syndrome Patients with Constipation (IBS-C), Irritable Bowel Syndrome Patients with Diarrhea (IBS-D) |
Primary outcome
Total fecal bile acids
Time frame: 48 hours
Stool samples will be collected over 2 days for measurement of fecal bile acids (µmol/48h) by high performance liquid chromatography-mass spectometry.
Total fecal short chain fatty acids
Time frame: 48 hours
Stool samples will be collected for measurement of measurement of short chain fatty acids (µg/mg) by liquid chromatography-mass spectrometry
Individual fecal short chain fatty acids
Time frame: 48 hours
Stool samples will be collected for measurement of measurement of short chain fatty acids (µg/mg) by liquid chromatography-mass spectrometry
Fecal microbial population
Time frame: 48 hours
Stool samples will be be collected from participants for nucleic acid extraction, 16S allele PCR and sequencing to measure microbial communities and profiles of specimens
Fecal inulin
Time frame: 48 hours
Fecal inulin content will be measured using short acid hydrolysis and high-performance liquid chromatography
2 secondary outcomes
Percent primary fecal bile acids
Time frame: 48 hours
Stool characteristics
Time frame: 4 days
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 Aug 2026.
- Background: PubMed 21876564Wong BS, Camilleri M, McKinzie S, Burton D, Graffner H, Zinsmeister AR. Effects of A3309, an ileal bile acid transporter inhibitor, on colonic transit and symptoms in females with functional constipation. Am J Gastroenterol. 2011 Dec;106(12):2154-64. doi: 10.1038/ajg.2011.285. Epub 2011 Aug 30.
- Background: PubMed 21606974Chey WD, Camilleri M, Chang L, Rikner L, Graffner H. A randomized placebo-controlled phase IIb trial of a3309, a bile acid transporter inhibitor, for chronic idiopathic constipation. Am J Gastroenterol. 2011 Oct;106(10):1803-12. doi: 10.1038/ajg.2011.162. Epub 2011 May 24.
- Background: PubMed 25329562Walters JR, Johnston IM, Nolan JD, Vassie C, Pruzanski ME, Shapiro DA. The response of patients with bile acid diarrhoea to the farnesoid X receptor agonist obeticholic acid. Aliment Pharmacol Ther. 2015 Jan;41(1):54-64. doi: 10.1111/apt.12999. Epub 2014 Oct 20.
- Background: PubMed 11254495Musch MW, Bookstein C, Xie Y, Sellin JH, Chang EB. SCFA increase intestinal Na absorption by induction of NHE3 in rat colon and human intestinal C2/bbe cells. Am J Physiol Gastrointest Liver Physiol. 2001 Apr;280(4):G687-93. doi: 10.1152/ajpgi.2001.280.4.G687.
- Background: PubMed 2732869Murray RD, McClung HJ, Li BU, Ailabouni A. Stimulatory effects of short-chain fatty acids on colonic absorption in newborn piglets in vivo. J Pediatr Gastroenterol Nutr. 1989 Jan;8(1):95-101. doi: 10.1097/00005176-198901000-00018.
- Background: PubMed 12676748Fukumoto S, Tatewaki M, Yamada T, Fujimiya M, Mantyh C, Voss M, Eubanks S, Harris M, Pappas TN, Takahashi T. Short-chain fatty acids stimulate colonic transit via intraluminal 5-HT release in rats. Am J Physiol Regul Integr Comp Physiol. 2003 May;284(5):R1269-76. doi: 10.1152/ajpregu.00442.2002.
- Background: PubMed 16078948Mitsui R, Ono S, Karaki S, Kuwahara A. Neural and non-neural mediation of propionate-induced contractile responses in the rat distal colon. Neurogastroenterol Motil. 2005 Aug;17(4):585-94. doi: 10.1111/j.1365-2982.2005.00669.x.
- Background: PubMed 22738315Banasiewicz T, Krokowicz L, Stojcev Z, Kaczmarek BF, Kaczmarek E, Maik J, Marciniak R, Krokowicz P, Walkowiak J, Drews M. Microencapsulated sodium butyrate reduces the frequency of abdominal pain in patients with irritable bowel syndrome. Colorectal Dis. 2013 Feb;15(2):204-9. doi: 10.1111/j.1463-1318.2012.03152.x.
- Background: PubMed 3033815Mortensen PB, Andersen JR, Arffmann S, Krag E. Short-chain fatty acids and the irritable bowel syndrome: the effect of wheat bran. Scand J Gastroenterol. 1987 Mar;22(2):185-92. doi: 10.3109/00365528708991878.
- Background: PubMed 19903265Tana C, Umesaki Y, Imaoka A, Handa T, Kanazawa M, Fukudo S. Altered profiles of intestinal microbiota and organic acids may be the origin of symptoms in irritable bowel syndrome. Neurogastroenterol Motil. 2010 May;22(5):512-9, e114-5. doi: 10.1111/j.1365-2982.2009.01427.x. Epub 2009 Nov 10.
- Background: PubMed 8890079Treem WR, Ahsan N, Kastoff G, Hyams JS. Fecal short-chain fatty acids in patients with diarrhea-predominant irritable bowel syndrome: in vitro studies of carbohydrate fermentation. J Pediatr Gastroenterol Nutr. 1996 Oct;23(3):280-6. doi: 10.1097/00005176-199610000-00013.
- Background: PubMed 25531553Aguilera M, Cerda-Cuellar M, Martinez V. Antibiotic-induced dysbiosis alters host-bacterial interactions and leads to colonic sensory and motor changes in mice. Gut Microbes. 2015;6(1):10-23. doi: 10.4161/19490976.2014.990790. Epub 2015 Jan 20.
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Irritable Bowel Syndrome, Constipation
RecruitingPhase 2
A Study of Brenipatide (LY3537031) in Participants With Irritable Bowel Syndrome-Diarrhea (IBS-D)
Irritable Bowel Syndrome, Diarrhea
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
University of California, Los Angeles
Los Angeles, United States
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Inulin in people with Irritable Bowel Syndrome (IBS), run by University of California, Los Angeles at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 12 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Total fecal bile acids (time frame: 48 hours). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06668922, which also lists 71 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 Aug 2026.