Citrus Beverages and Gastrointestinal Function

Not Applicable

Completed

• Conditions: Healthy
• Interventions: Dietary Supplement: Flavored water (control); Dietary Supplement: 180 g pomace; Dietary Supplement: 0 g pomace (control); Dietary Supplement: 90 g pomace

• Registration Number: NCT02979496
• Lead Sponsor: University of Florida

Brief Summary

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

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.

Study Timeline

• Study First Submitted: 2016-11-29
• Study First Submitted QC: 2016-11-29
• Study First Posted: 2016-12-01
• Study Start: 2017-02-13
• Primary Completion: 2017-04-29
• Study Completion: 2017-04-29
• Status Verified: 2018-10
• Last Update Submitted: 2018-10-11
• Last Update Posted: 2018-10-16

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 330

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

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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

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Flavored water (control)	Flavored water (control)	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).
180 g pomace	180 g pomace	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).
0 g pomace (control)	0 g pomace (control)	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).
90 g pomace	90 g pomace	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).

Primary Outcome Measures

Name	Time	Method
Change in Stool Frequency	Weeks -1,0,1,2,3	The average number of stools per week compared between intervention groups.

Secondary Outcome Measures

Name	Time	Method
Change in Number of bifidobacteria in fecal samples	Change from Weeks 0 and 3	Bifidobacteria in fecal samples will be quantified via quantitative polymerase chain reaction (qPCR) and compared between groups.
Change in Fasting blood glucose	Change from Weeks 0 and 3	Fasting blood glucose determined by Cholestech assay
Change in Reflux symptom score	Change from Weeks -1,0,1,2,3	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 in Stool frequency as a function of stool consistency	Change from Weeks -1,0,1,2,3	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 in Diarrhea symptom score	Change from Weeks -1,0,1,2,3	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 in Constipation symptom score	Change from Weeks -1,0,1,2,3	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 in Indigestion symptom score	Change from Weeks -1,0,1,2,3	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 in Abdominal pain symptom score	Change from Weeks -1,0,1,2,3	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.

Trial Locations

Locations (1)

University of Florida; 🇺🇸 Gainesville, Florida, United States