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Clinical trial information and results are updated daily from ClinicalTrials.gov. The latest data update was conducted on 06/15/2021.

Impact of Blueberry Consumption on Gastrointestinal Health

Clinicaltrials.gov identifier NCT03934177

Recruitment Status Enrolling by invitation

First Posted May 1, 2019

Last update posted February 21, 2021

Study Description

Brief summary:

This study will evaluate the impact of blueberry consumption on markers of gastrointestinal health including gut microbiota, intestinal permeability, and gut-derived inflammation in those vulnerable to a unhealthy gut milieu. All participants will consume a blueberry powder and a placebo in this crossover study.

  • Condition or Disease:Circadian Dysregulation
  • Intervention/Treatment: Dietary Supplement: Blueberry powder
    Dietary Supplement: Placebo powder
  • Phase: N/A
Detailed Description

The commensal bacteria that reside in the human gut, known as the gut microbiota, is a complex system that modulates local gut homeostasis and systemic biological processes. Several environmental factors have been shown to influence the gut milieu (including microbiota), and thus both gastrointestinal and host health. Relevant to the current proposal is the influence of body weight, diet, and circadian rhythms. In the current study, the investigators propose to use these common disruptors of gastrointestinal health through recruiting obese shift workers with a low-fiber diet to identify if these disrupted individuals can benefit from blueberry intake. Specifically, the study objectives are to determine if 21 g whole blueberry powder consumed daily can beneficially modify intestinal permeability, gut microbiota, microbial metabolites, and both gut-derived and systemic inflammation in those most susceptible to a pro-inflammatory milieu. This will be accomplished through a 14-week crossover study in which 28 individuals will be randomized by treatment group order to 4 weeks of whole blueberry powder and placebo powder, with a 4-week wash out in between the treatment periods.

Study Design
  • Study Type: Interventional
  • Estimated Enrollment: 28 participants
  • Allocation: Randomized
  • Intervention Model: Crossover Assignment
  • Intervention Model Description: This 14-week crossover study includes 4 weeks for each of the two supplementation periods (blueberries and placebo), with a 4-week wash out between.
  • Masking: Triple (Participant, Investigator, Outcomes Assessor)
  • Primary Purpose: Treatment
  • Official Title: Impact of Blueberry Consumption on Intestinal Permeability, Gut Microbiota, and Gut-Derived Inflammation in Individuals With Elevated Risk of a Pro-Inflammatory Gut Milieu
  • Actual Study Start Date: March 2019
  • Estimated Primary Completion Date: May 2021
  • Estimated Study Completion Date: May 2021
Arms and interventions
Arm Intervention/treatment
Experimental: Blueberry powder
4 weeks of supplementation of 21 g whole blueberry powder
Dietary Supplement: Blueberry powder
Dried, powdered blueberries will be consumed at 21 g/day in two divided doses at least 4 hours apart.
Placebo Comparator: Placebo powder
4 weeks of supplementation of 21 g placebo powder (maltodextrin)
Dietary Supplement: Placebo powder
A placebo consisting maltodextrin will be consumed at 21 g/day in two divided doses at least 4 hours apart.
Outcome Measures
  • Primary Outcome Measures: 1. intestinal permeability [ Time Frame: 28 days ]
    urinary sugar measurement by gas chromatography (GC): Sucralose, lactulose, mannitol, sucrose as a percent of oral dose.
  • Secondary Outcome Measures: 1. Microbiota [ Time Frame: 28 days ]
    Microbiota composition through shotgun sequencing. Composition includes relative abundance of all microbes in stool.
  • 2. Microbial metabolites [ Time Frame: 28 days ]
    Quantity of stool short-chain fatty acid (butyrate, propionate, acetate) per dry stool weight by gas chromatography
  • 3. Gut-derived/systemic inflammation [ Time Frame: 28 days ]
    Concentration of serum lipopolysaccharide (LPS), LPS-binding protein (LBP), and interleukin-6 (IL6)
Eligibility Criteria
  • Ages Eligible for Study: 19 to 70 Years (Adult, Older Adult)
  • Sexes Eligible for Study: All
  • Accepts Healthy Volunteers: Yes

Inclusion Criteria:

- obese (BMI +/- 30.0 kg/m2)

- shift workers (shift work overnight (third shift) +/= 3 days/week for the past 3

- 19-70 years of age

Exclusion Criteria:

- patient history of gastrointestinal diseases except for hiatal hernia, GERD, or
hemorrhoids, mild gastrointestinal symptoms

- elevated laboratory values from a comprehensive metabolic panel (CMP) and complete
blood count (CBC) with the exception of glucose (+/= 126 mg/dL; if elevated, confirmed
with HA1c of greater than or equal to 6.5%) and ALT, AST, or ALP over 2 times normal
levels (to allow for mild elevations resulting from fatty liver often seen in obese)
unless approved by study physician

- currently pregnant or plans to become pregnant during the study as determined by
participant report

- antibiotic use within the last 12 weeks prior to enrollment

- presence of chronic metabolic disease (e.g., cardiovascular disease, diabetes, cancer)
or per physician discretion

- recent (past 4 weeks) major change in dietary habits or a plan to have a major change
in dietary habits during the study

- habitual blueberry consumption of more than 0.5 cups 2x/week or a 4-week washout
period if consumes

- allergy or intolerance to blueberries

- consumption of supplemental fiber, probiotics or prebiotics without an appropriate
4-week washout period

- restrictive dietary patterns (e.g., ketogenic, Paleolithic) or a diet high in fiber
(+/= 14 g/1000 kilocalories) to increase study result generalizability to the U.S.
population (low-fiber diet), as well as provide another stimuli for gut leakiness

- unwillingness to consent to the study.

Contacts and Locations

United States, Nebraska
University of Nebraska

Sponsors and Collaborators

University of Nebraska Lincoln

Rush University Medical Center


Principal Investigator: Heather E Rasmussen, PhD University of Nebraska Lincoln

More Information
  • Responsible Party: University of Nebraska Lincoln
  • ClinicalTrials.gov Identifier: NCT03934177 History of Changes
  • Other Study ID Numbers: 18557
  • First Posted: May 1, 2019 Key Record Dates
  • Last Update Posted: February 21, 2021
  • Last Verified: February 2021
  • Individual Participant
    Data (IPD) Sharing
  • Plan to Share IPD: No
  • Studies a U.S. FDA-regulated Drug Product: No
  • Studies a U.S. FDA-regulated Device Product: No
  • Keywords provided by University of Nebraska Lincoln: Blueberry
    Intestinal permeability
  • Additional relevant MeSH terms: Chronobiology Disorders