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.
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.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
29
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.
Indiana University
Indianapolis, Indiana, United States
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
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
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
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
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
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
Fecal Inulin
Fecal inulin content will be measured using short acid hydrolysis and high-performance liquid chromatography
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Time frame: 48 hours
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
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
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
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