Citrus Beverages and Gastrointestinal Function

Study Overview
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Brief Summary
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The purpose of this study is to evaluate the effect of daily intake of orange pomace on gastrointestinal function as measured by stool frequency. Additional outcomes will include aspects of digestive health, diet quality, and fasting blood glucose and lipid concentrations. Possible explanations for the mechanism of the pomace will be explored in microbial ecology analyses.

Detailed Description
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In this randomized, double-blind, controlled trial, healthy adults will be asked to consume daily servings of orange juice containing either 0 g (n=120; control) or 180 g (i.e. 10 g fiber; n=120) of orange pomace for 3 weeks to assess the effect of the pomace on stool frequency. Blood samples will be obtained to assess the effect of the pomace on metabolic markers. Stool samples will be collected for analyses of the effect of the pomace on fecal bacteria known to be associated with health benefits (e.g., bifidobacteria). For exploratory analyses, additional groups will be asked to consume orange juice containing 90 g of pomace (i.e. 5 g fiber; n=40) or orange-flavored, calorie-matched water (n=40); outcomes from the water group will be compared to those of the 0 g pomace juice group to assess any effects of the juice alone, and outcomes from the 90 g pomace group will be compared to those of the 180 g and 0 g groups in microbiota analyses.

Official Title
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The Effect of Citrus Beverages on Gastrointestinal Function in Healthy Adults: a Randomized, Double-blind, Controlled Clinical Trial

Conditions
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Healthy

Intervention / Treatment
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* Dietary Supplement: 0 g pomace (control)
* Dietary Supplement: 90 g pomace
* Dietary Supplement: 180 g pomace
* Dietary Supplement: Flavored water (control)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy adults 18-60 years of age Willing and able to consume 16 oz. of a citrus beverage daily for the 3-week study intervention Willing and able to avoid consumption of any orange, grapefruit, tomato or V-8 juice and whole oranges or grapefruits during the two weeks leading up to the study and during the study, not including the study beverage Willing and able to complete daily questionnaires online regarding dietary intake and general health and well-being, including gastrointestinal habits Note: we will recruit participants who will have Internet access for the duration of the protocol, but understand that, once enrolled, situations may change. If this is the case, paper copies of the online forms will be provided Willing to discontinue any prebiotic, probiotic, and fiber supplements after consenting Willing to provide blood via finger prick and a stool sample twice each, once at the beginning and once at the end of the study Exclusion Criteria: Women who are lactating, know that they are pregnant, or are attempting to get pregnant Currently being treated for any physician-diagnosed diseases or conditions Vegetarians/vegans

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: 0 g pomace (control)<br>16 oz of juice containing 0 g of citrus pomace will be consumed each day for 3 weeks by participants in the group receiving this assignment (group is unknown, double-blinded). | Dietary Supplement: 0 g pomace (control)<br>* 16 oz of juice containing 0 g of citrus pomace will be consumed each day for 3 weeks by participants in the group receiving this assignment (group is unknown, double-blinded)<br>|
| Experimental: 90 g pomace<br>16 oz of juice containing 90 g of citrus pomace will be consumed each day for 3 weeks by participants in the group receiving this assignment (group is unknown, double-blinded). | Dietary Supplement: 90 g pomace<br>* 16 oz of juice containing 90 g of citrus pomace will be consumed each day for 3 weeks by participants in the group receiving this assignment (group is unknown, double-blinded).<br>|
| Experimental: 180 g pomace<br>16 oz of juice containing 180 g of citrus pomace will be consumed each day for 3 weeks by participants in the group receiving this assignment (group is unknown, double-blinded). | Dietary Supplement: 180 g pomace<br>* 16 oz of juice containing 180 g of citrus pomace will be consumed each day for 3 weeks by participants in the group receiving this assignment (group is unknown, double-blinded).<br>|
| Other: Flavored water (control)<br>16 oz of a flavored, calorie-matched water beverage will be consumed each day for 3 weeks by participants in the group receiving this assignment (group is unknown, double-blinded). | Dietary Supplement: Flavored water (control)<br>* 16 oz of a flavored, calorie-matched water beverage will be consumed each day for 3 weeks by participants in the group receiving this assignment (group is unknown, double-blinded).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Stool Frequency | The average number of stools per week compared between intervention groups. | Weeks -1,0,1,2,3 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Stool frequency as a function of stool consistency | The average number of stools per week compared between intervention groups, including Bristol Stool Score category (stool types 1-7 with 1 = hard and 7 = liquid ) as a covariate in the statistical model. | Change from Weeks -1,0,1,2,3 | 
| Change in Diarrhea symptom score | Measured By Gastrointestinal Symptom Response Scale (GSRS). Questionnaire asks participants about the previous seven days. Scores range from 1 (no discomfort) to 7 (very severe discomfort); lower scores are more desirable. | Change from Weeks -1,0,1,2,3 | 
| Change in Constipation symptom score | Measured By Gastrointestinal Symptom Response Scale (GSRS). Questionnaire asks participants about the previous seven days. Scores range from 1 (no discomfort) to 7 (very severe discomfort); lower scores are more desirable. | Change from Weeks -1,0,1,2,3 | 
| Change in Indigestion symptom score | Measured By Gastrointestinal Symptom Response Scale (GSRS). Questionnaire asks participants about the previous seven days. Scores range from 1 (no discomfort) to 7 (very severe discomfort); lower scores are more desirable. | Change from Weeks -1,0,1,2,3 | 
| Change in Reflux symptom score | Measured By Gastrointestinal Symptom Response Scale (GSRS). Questionnaire asks participants about the previous seven days. Scores range from 1 (no discomfort) to 7 (very severe discomfort); lower scores are more desirable. | Change from Weeks -1,0,1,2,3 | 
| Change in Abdominal pain symptom score | Measured By Gastrointestinal Symptom Response Scale (GSRS). Questionnaire asks participants about the previous seven days. Scores range from 1 (no discomfort) to 7 (very severe discomfort); lower scores are more desirable. | Change from Weeks -1,0,1,2,3 | 
| Change in Number of bifidobacteria in fecal samples | Bifidobacteria in fecal samples will be quantified via quantitative polymerase chain reaction (qPCR) and compared between groups. | Change from Weeks 0 and 3 | 
| Change in Fasting blood glucose | Fasting blood glucose determined by Cholestech assay | Change from Weeks 0 and 3 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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citrus, immune