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TerminatedNCT03983434Updated Apr 30, 2025Results posted

Irritable Bowel Syndrome and Control Volunteers: Diet Challenge

An interventional study of Inulin in IBS - Irritable Bowel Syndrome, sponsored by Indiana University. Terminated at 1 site in United States. Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-04-30.

Sponsored by Indiana University · Not applicable, Interventional, and Diagnostic

Why this study was terminated
Study physician left the university
Phase
Not applicable
Study type
Interventional
Enrollment
29
Allocation
Non-randomized
Ages
18 Years to 65 Years
Sex
All
01

Study summary

The purpose of this study is to study the relationship between the bile acids, short chain fatty acids and bacteria within the intestines. The hypothesis is that changes in the bacterial composition of the stool are associated with the differences in bile acids and short chain fatty acids in patients having irritable bowel syndrome compared to healthy individuals.

Read the detailed description

The Study involves 3 visits and will in include 3 types of subjects - those who have irritable bowel syndrome (IBS) with constipation (IBS-C), IBS with diarrhea (IBS-D) and those who have no IBS symptoms or diagnosis.

Visit 1

  • Volunteers will read and sign this informed consent after all questions about the study have been answered
  • This is a screening visit and we may determine that volunteers ineligible to continue to participate in the study.
  • Volunteers will have a medical history taken including demographics, history of symptoms and illness
  • Volunteers will be asked about all medications
  • A physical exam will be performed by the physician.
  • Vital signs will be measured.
  • Urine Pregnancy test may be done for woman in the reproductive age range.
  • Eligible participants will be provided with a take-home lasagna meal.
  • Participants will be given instructions and supplies for collection, storage and transportation of stool for the next visit.
  • Participants will be provided with instructions for a low fiber, high fat diet which should be consumed for 2 days before stool collection and during the 2 days of stool collection. Instructions will also come with materials to allow participants to record diet intake during these 4 days.
  • Participants will be provided a bowel pattern diary to record bowel symptoms over the course of the study

Day 1: this may be the same as Visit 1 or it may be a different day. It will depend upon the day that participants can make it back to the clinic for the Day 5 visit.

Day 2-4 (at home):

  • Participants record stool symptoms and patterns in a diary daily starting from Day 2 to Day 5.
  • During this time, participants will be instructed to consume a low fiber diet, avoid alcohol, and start a 4-day 100 g fat diet.
  • On the evening before Day 5, a standardized, completely digestible, and non-fermentable meal (lasagna) will be consumed which will be provided to you on Day 1.
  • Participants will collect stool at home on Day 4 and 5 and store as per instructions provided on Visit 1. They will

Day 5 (Visit 2):

  • Participants return to the clinic on Day 5 after an overnight fast.
  • You will receive a standard breakfast and lasanga meal with 10 g inulin (Orafti®) powder and 200 mL of water.
  • Take-home meals will be provided (white bread sandwich with ham or cheese) to be consumed at 4 and 8 hours after breakfast.

Day 6 (Visit 3):

  • Participants will return to the clinic in order to return stool collections and the daily diaries.
  • Participants may also submit diaries by fax or email.

Day 30-90

  • Optional dietary follow-up (Day 30-90): 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.
02

Conditions studied

  • IBS - Irritable Bowel Syndrome

Keywords

  • microbiome
  • microbiota
  • short chain fatty acids
  • prebiotic
  • bile acids
03

In context

Irritable Bowel Syndrome

1,062 studies on the registry are indexed under Irritable Bowel Syndrome; 190 are open to participants now.

This study's enrollment of 29 is below the median of 71 across 853 interventional studies indexed under Irritable Bowel Syndrome.

Browse Irritable Bowel Syndrome studies →

Lead sponsor

Indiana University is the lead sponsor of 958 studies on the registry; 200 are open to participants now.

Of its 142 completed or terminated interventional studies of FDA-regulated products, 112 (79%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 65 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • Patients with IBS, ages 18-65 fulfilling Rome IV criteria and asymptomatic controls with no prior history of GI disease or symptoms.
  • Participants should be on a stable and consistent diet regimen and should not be following an extreme diet intervention such as gluten-free or a low FODMAP diet at the time of study participation.

Exclusion criteria

Exclusion Criteria:

  • Participants with microscopic/lymphocytic/collagenous colitis, inflammatory bowel disease, celiac disease, visceral cancer, chronic infectious disease, immunodeficiency, uncontrolled thyroid disease, history of liver disease or history of elevated AST/ALT > 2.0x the upper limit of normal
  • Prior radiation therapy of the abdomen or abdominal surgeries except for C-section, tubal ligation, vaginal hysterectomy and appendectomy or cholecystectomy, > 6 months prior to study initiation.
  • Ingestion of any prescription, over the counter, or herbal medications which can affect GI transit or study interpretation (e.g. opioids, narcotics, anticholinergics, norepinephrine reuptake inhibitors, nonsteroidal anti-inflammatory drugs, COX-2 inhibitors, bile acid sequestrants) within 6 months of study initiation for asymptomatic volunteers or within 2 days before study initiation for IBS patients. Rescue therapy to facilitate stool collection will be permitted where needed.
  • Any females who are pregnant or trying to become pregnant or breast-feeding
  • Antibiotic usage within 3 months prior to study participation
  • Prebiotic or probiotic usage within the 2 weeks prior to study initiation
  • Regular use of tobacco products within the past 6 months.
05

Study design

Phase
Not applicable
Primary purpose
Diagnostic
Allocation
Non-randomized
Intervention model
Single group
Masking
None (open label)
Enrollment
29 participants (actual)

Study arms

  • Experimental
    Healthy volunteers

    Adults ages 18-65 years with no prior history of gastrointestinal diseases or symptoms.

    Dietary Supplement: Inulin

  • Experimental
    Irritable Bowel Syndrome Patients with Diarrhea

    Patients with irritable bowel syndrome (IBS) with diarrhea, ages 18-65 years fulfilling Rome IV criteria for IBS

    Dietary Supplement: Inulin

  • Experimental
    Irritable Bowel Syndrome Patients with Constipation

    Patients with irritable bowel syndrome (IBS) with constipation, ages 18-65 years fulfilling Rome IV criteria for IBS

    Dietary Supplement: Inulin

Interventions

  • Dietary supplementInulin

    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.

06

What researchers measure

Primary outcomes

  1. Total Fecal Bile Acids

    Stool samples will be collected over 2 days for measurement of fecal bile acids (mcmol/48h) by high performance liquid chromatography-mass spectometry

    Time frame: 48 hours

  2. Total Fecal Short Chain Fatty Acids

    Stool samples will be collected for measurement of measurement of short chain fatty acids (mmol/kg) by liquid chromatography-mass spectrometry

    Time frame: 48 hours

  3. Individual Fecal Short Chain Fatty Acids - Acetate

    Stool samples will be collected for measurement of measurement of short chain fatty acids (mmol/kg) by liquid chromatography-mass spectrometry

    Time frame: 48 hours

  4. Individual Fecal Short Chain Fatty Acids - Propionate

    Stool samples will be collected for measurement of measurement of short chain fatty acids (mmol/kg) by liquid chromatography-mass spectrometry

    Time frame: 48 hours

  5. Individual Fecal Short Chain Fatty Acids - Butyrate

    Stool samples will be collected for measurement of measurement of short chain fatty acids (mmol/kg) by liquid chromatography-mass spectrometry

    Time frame: 48 hours

  6. Fecal Microbial Population

    Stool samples will be be collected from participants for nucleic acid extraction, shotgun sequencing is used to measure microbial communities and profiles of specimens. Shannon index is calculated to measure the diversity of species. The minimum value is 0. There is no upper limit. The higher the Shannon index is, the greater the diversity of species is.

    Time frame: 48 hours

  7. Fecal Inulin

    Fecal inulin content will be measured using short acid hydrolysis and high-performance liquid chromatography

    Time frame: 48 hours

Secondary outcomes

  1. Percent Primary Fecal Bile Acids

    Stool samples will be collected over 2 days for measurement of fecal bile acids (mcmol/48h) by high performance liquid chromatography-mass spectrometry. Percent primary bile acids is then calculated as primary bile acids divided by total bile acids multiplied by 100.

    Time frame: 48 hours

  2. Stool Characteristics - Stool Frequency in 4 Days

    Stool characteristics will be measured using a 4 day bowel diary. Stool frequency is the total number of bowel movements in 4 days summarized on the subject level.

    Time frame: 4 days

  3. Stool Characteristics - Stool Form

    Stool characteristics will be measured using a 4 day bowel diary. Stool form is on a scale from 1 to 7, where 1=hard lumps, 2=lumps sausage,3=cracked sausage, 4=normal, 5=soft lumps, 6=mushy,7=watery, summarized on the level of bowel movements.

    Time frame: 4 days

  4. Stool Characteristics - Ease of Passage

    Stool characteristics will be measured using a 4 day bowel diary. Ease of passage is on a scale from 1 to 7, where 1=manual disimpaction, 2=enema needed, 3=straining needed, 4=normal, 5=urgent without pain, 6=urgent with pain, 7=incontinent, also summarized on the level of bowel movements.

    Time frame: 4 days

Other outcomes

  1. Energy

    Optional 24-hour dietary intake will be submitted using web-based Automated Self-Administered Dietary Assessment Tool developed by the National Cancer Institute (https://epi.grants.cancer.gov/asa24/). Dietary intake within a 24-hour period in 30-90 days after study enrollment were collected.

    Time frame: 24 hours

07

Results

Posted Apr 30, 2025

Participant flow

Participant flow — Overall Study
MilestoneHealthy VolunteersIrritable Bowel Syndrome Patients With ConstipationIrritable Bowel Syndrome Patients With Diarrhea
Started1739
Completed1626
Not completed113

Outcome measures

PrimaryTotal Fecal Bile Acids

Stool samples will be collected over 2 days for measurement of fecal bile acids (mcmol/48h) by high performance liquid chromatography-mass spectometry

Time frame:
48 hours
Reported as:
Median · mcmol/48 hours
Total Fecal Bile Acids
mcmol/48 hoursHealthy VolunteersIrritable Bowel Syndrome Patients With ConstipationIrritable Bowel Syndrome Patients With Diarrhea
Total Fecal Bile Acids471.5 (331.5 to 612.5)347 (159 to 535)329.5 (145 to 515)
Statistical analysis
  • Healthy Volunteers vs Irritable Bowel Syndrome Patients With Constipation vs Irritable Bowel Syndrome Patients With Diarrhea · Kruskal-Wallis · p = .62
PrimaryTotal Fecal Short Chain Fatty Acids

Stool samples will be collected for measurement of measurement of short chain fatty acids (mmol/kg) by liquid chromatography-mass spectrometry

Time frame:
48 hours
Reported as:
Median · mmol/kg
Total Fecal Short Chain Fatty Acids
mmol/kgHealthy VolunteersIrritable Bowel Syndrome Patients With ConstipationIrritable Bowel Syndrome Patients With Diarrhea
Total Fecal Short Chain Fatty Acids359.8 (233.1 to 473.2)157.1 (157.1 to 157.1)276.9 (168.6 to 408.1)
Statistical analysis
  • Healthy Volunteers vs Irritable Bowel Syndrome Patients With Constipation vs Irritable Bowel Syndrome Patients With Diarrhea · Kruskal-Wallis · p = 0.17
PrimaryIndividual Fecal Short Chain Fatty Acids - Acetate

Stool samples will be collected for measurement of measurement of short chain fatty acids (mmol/kg) by liquid chromatography-mass spectrometry

Time frame:
48 hours
Reported as:
Median · mmol/kg
Individual Fecal Short Chain Fatty Acids - Acetate
mmol/kgHealthy VolunteersIrritable Bowel Syndrome Patients With ConstipationIrritable Bowel Syndrome Patients With Diarrhea
Individual Fecal Short Chain Fatty Acids - Acetate255.7 (147.5 to 300.1)113.9 (113.9 to 113.9)202.5 (121.7 to 266)
Statistical analysis
  • Healthy Volunteers vs Irritable Bowel Syndrome Patients With Constipation vs Irritable Bowel Syndrome Patients With Diarrhea · Kruskal-Wallis · p = 0.17
PrimaryIndividual Fecal Short Chain Fatty Acids - Propionate

Stool samples will be collected for measurement of measurement of short chain fatty acids (mmol/kg) by liquid chromatography-mass spectrometry

Time frame:
48 hours
Reported as:
Median · mmol/kg
Individual Fecal Short Chain Fatty Acids - Propionate
mmol/kgHealthy VolunteersIrritable Bowel Syndrome Patients With ConstipationIrritable Bowel Syndrome Patients With Diarrhea
Individual Fecal Short Chain Fatty Acids - Propionate59.7 (39.8 to 86)22.8 (22.8 to 22.8)39.1 (25.3 to 51.1)
Statistical analysis
  • Healthy Volunteers vs Irritable Bowel Syndrome Patients With Constipation vs Irritable Bowel Syndrome Patients With Diarrhea · Kruskal-Wallis · p = 0.079
PrimaryIndividual Fecal Short Chain Fatty Acids - Butyrate

Stool samples will be collected for measurement of measurement of short chain fatty acids (mmol/kg) by liquid chromatography-mass spectrometry

Time frame:
48 hours
Reported as:
Median · mmol/kg
Individual Fecal Short Chain Fatty Acids - Butyrate
mmol/kgHealthy VolunteersIrritable Bowel Syndrome Patients With ConstipationIrritable Bowel Syndrome Patients With Diarrhea
Individual Fecal Short Chain Fatty Acids - Butyrate57.5 (29.1 to 70.2)20.5 (20.5 to 20.5)37.6 (16.9 to 91)
Statistical analysis
  • Healthy Volunteers vs Irritable Bowel Syndrome Patients With Constipation vs Irritable Bowel Syndrome Patients With Diarrhea · Kruskal-Wallis · p = 0.47
PrimaryFecal Microbial Population

Stool samples will be be collected from participants for nucleic acid extraction, shotgun sequencing is used to measure microbial communities and profiles of specimens. Shannon index is calculated to measure the diversity of species. The minimum value is 0. There is no upper limit. The higher the Shannon index is, the greater the diversity of species is.

Time frame:
48 hours
Reported as:
Median · units on a scale
Fecal Microbial Population
units on a scaleHealthy VolunteersIrritable Bowel Syndrome Patients With ConstipationIrritable Bowel Syndrome Patients With Diarrhea
Fecal Microbial Population3 (2.75 to 3.5)—3.6 (3.2 to 3.8)
PrimaryFecal Inulin

Fecal inulin content will be measured using short acid hydrolysis and high-performance liquid chromatography

Time frame:
48 hours
Reported as:
Median · % of fructose from inulin/total fructose
Fecal Inulin
% of fructose from inulin/total fructoseHealthy VolunteersIrritable Bowel Syndrome Patients With ConstipationIrritable Bowel Syndrome Patients With Diarrhea
Fecal Inulin3.6 (0.8 to 5.4)—17.1 (7.4 to 25)
Statistical analysis
  • Healthy Volunteers vs Irritable Bowel Syndrome Patients With Diarrhea · Kruskal-Wallis · p = 0.03
SecondaryPercent Primary Fecal Bile Acids

Stool samples will be collected over 2 days for measurement of fecal bile acids (mcmol/48h) by high performance liquid chromatography-mass spectrometry. Percent primary bile acids is then calculated as primary bile acids divided by total bile acids multiplied by 100.

Time frame:
48 hours
Reported as:
Median · % of primary/total fecal bile acids
Percent Primary Fecal Bile Acids
% of primary/total fecal bile acidsHealthy VolunteersIrritable Bowel Syndrome Patients With ConstipationIrritable Bowel Syndrome Patients With Diarrhea
Percent Primary Fecal Bile Acids2.7 (1 to 26.8)0.4 (0.3 to 0.5)2.1 (0.6 to 10.3)
Statistical analysis
  • Healthy Volunteers vs Irritable Bowel Syndrome Patients With Constipation vs Irritable Bowel Syndrome Patients With Diarrhea · Kruskal-Wallis · p = 0.14
SecondaryStool Characteristics - Stool Frequency in 4 Days

Stool characteristics will be measured using a 4 day bowel diary. Stool frequency is the total number of bowel movements in 4 days summarized on the subject level.

Time frame:
4 days
Reported as:
Median · Number of bowel movements in 4 days
Stool Characteristics - Stool Frequency in 4 Days
Number of bowel movements in 4 daysHealthy VolunteersIrritable Bowel Syndrome Patients With ConstipationIrritable Bowel Syndrome Patients With Diarrhea
Stool Characteristics - Stool Frequency in 4 Days4.5 (4 to 5.5)0.5 (0 to 1)5 (2 to 10)
Statistical analysis
  • Healthy Volunteers vs Irritable Bowel Syndrome Patients With Constipation vs Irritable Bowel Syndrome Patients With Diarrhea · Kruskal-Wallis · p = 0.074
SecondaryStool Characteristics - Stool Form

Stool characteristics will be measured using a 4 day bowel diary. Stool form is on a scale from 1 to 7, where 1=hard lumps, 2=lumps sausage,3=cracked sausage, 4=normal, 5=soft lumps, 6=mushy,7=watery, summarized on the level of bowel movements.

Time frame:
4 days
Reported as:
Median · score on a scale
Stool Characteristics - Stool Form
score on a scaleHealthy VolunteersIrritable Bowel Syndrome Patients With ConstipationIrritable Bowel Syndrome Patients With Diarrhea
Stool Characteristics - Stool Form4 (3 to 5)1 (1 to 1)5 (4 to 6)
Statistical analysis
  • Healthy Volunteers vs Irritable Bowel Syndrome Patients With Constipation vs Irritable Bowel Syndrome Patients With Diarrhea · Kruskal-Wallis · p = 0.004
SecondaryStool Characteristics - Ease of Passage

Stool characteristics will be measured using a 4 day bowel diary. Ease of passage is on a scale from 1 to 7, where 1=manual disimpaction, 2=enema needed, 3=straining needed, 4=normal, 5=urgent without pain, 6=urgent with pain, 7=incontinent, also summarized on the level of bowel movements.

Time frame:
4 days
Reported as:
Median · score on a scale
Stool Characteristics - Ease of Passage
score on a scaleHealthy VolunteersIrritable Bowel Syndrome Patients With ConstipationIrritable Bowel Syndrome Patients With Diarrhea
Stool Characteristics - Ease of Passage4 (4 to 4)3 (3 to 3)4 (4 to 5)
Statistical analysis
  • Healthy Volunteers vs Irritable Bowel Syndrome Patients With Constipation vs Irritable Bowel Syndrome Patients With Diarrhea · Kruskal-Wallis · p = 0.17
Other pre-specifiedEnergy

Optional 24-hour dietary intake will be submitted using web-based Automated Self-Administered Dietary Assessment Tool developed by the National Cancer Institute (https://epi.grants.cancer.gov/asa24/). Dietary intake within a 24-hour period in 30-90 days after study enrollment were collected.

Time frame:
24 hours
Reported as:
Median · kcal
Energy
kcalHealthy VolunteersIrritable Bowel Syndrome Patients With ConstipationIrritable Bowel Syndrome Patients With Diarrhea
Energy1887.6 (1563.9 to 2507.5)2083.8 (1801.3 to 2366.4)2246.4 (1540.1 to 2509.8)
Statistical analysis
  • Healthy Volunteers vs Irritable Bowel Syndrome Patients With Constipation vs Irritable Bowel Syndrome Patients With Diarrhea · Kruskal-Wallis · p = 0.98

Adverse events

Collected over 3 months. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
Healthy Volunteers0/16 (0%)0/16 (0%)0/16 (0%)
Irritable Bowel Syndrome Patients With Constipation0/2 (0%)0/2 (0%)0/2 (0%)
Irritable Bowel Syndrome Patients With Diarrhea0/6 (0%)0/6 (0%)0/6 (0%)

Baseline characteristics

Age, Categorical
Age, Categorical(Participants)Healthy VolunteersIrritable Bowel Syndrome Patients With ConstipationIrritable Bowel Syndrome Patients With DiarrheaTotal
<=18 years0000
Between 18 and 65 years163928
>=65 years1001
Age, Continuous
Age, Continuous(years)Healthy VolunteersIrritable Bowel Syndrome Patients With ConstipationIrritable Bowel Syndrome Patients With DiarrheaTotal
Mean36.3 ± 14.926.4 ± 636.1 ± 9.535.2 ± 12.8
Sex: Female, Male
Sex: Female, Male(Participants)Healthy VolunteersIrritable Bowel Syndrome Patients With ConstipationIrritable Bowel Syndrome Patients With DiarrheaTotal
Female122721
Male5128
Ethnicity (NIH/OMB)
Ethnicity (NIH/OMB)(Participants)Healthy VolunteersIrritable Bowel Syndrome Patients With ConstipationIrritable Bowel Syndrome Patients With DiarrheaTotal
Hispanic or Latino0000
Not Hispanic or Latino173929
Unknown or Not Reported0000
Race (NIH/OMB)
Race (NIH/OMB)(Participants)Healthy VolunteersIrritable Bowel Syndrome Patients With ConstipationIrritable Bowel Syndrome Patients With DiarrheaTotal
American Indian or Alaska Native0000
Asian90110
Native Hawaiian or Other Pacific Islander0000
Black or African American0101
White82818
More than one race0000
Unknown or Not Reported0000
08

Study locations

1 site
  • Indiana University
    Indianapolis, Indiana 46202, United States
09

References and documents

Study documents

  • Protocol and statistical analysis plan · Oct 4, 2022

Documents are hosted by the registry — open the source record to download them.

10

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Apr 30, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
11

Registry details

Key details

Study ID
NCT03983434
Lead sponsor
Indiana University
Collaborators
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Responsible party
Huiping Xu (Associate Professor, Indiana University) — Principal investigator
First posted
Jun 12, 2019
Start date
Aug 13, 2019
Primary completion
Jul 31, 2023
Completion
Jul 31, 2023
Results posted
Apr 30, 2025
Last update
Apr 30, 2025

Study contacts

Huiping XU
principal investigator · Indiana University

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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