Effects of Grape Powder on Psychological Distress and Gut Microbiota in College Students

January 14, 2026 updated by: Guojun Wu, Ph.D., Rutgers, The State University of New Jersey

Effects of Grape Powder on Psychological Distress and Gut Microbiota in College Students (FTGP2025)

The goal of this trial is to investigate the effect of freeze-dried table grape powder (FTGP) on psychological distress and gut microbiota in college students. The main questions it aims to answer are:

Does FTGP reduce anxiety, depression, and perceived stress? Does FTGP improve the gut microbiota? Researchers will compare FTGP to a placebo to see how FTGP affects psychological distress and gut microbiota.

Participants will:

Drink a daily supplement containing FTGP or a placebo for 4 weeks. Record consumption of grape powder or placebo in a compliance log. Complete surveys and provide stool samples. Three in-person visits.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
50

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • New Jersey
      • New Brunswick, New Jersey, United States, 08901
        • Department of Biochemistry and Microbiology, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Aged 18-30 years old
  • Able to give written informed consent.
  • BMI 18.5-24.9 kg/m2
  • Healthy (self-reported)
  • Can read and speak English

Exclusion Criteria:

  • Currently taking medications that interfere with polyphenol
  • Currently using or have used antibiotics continuously for >3 days within 3 months prior to enrollment
  • Have had surgery involving the intestinal lumen within the last 30 days
  • Have a documented diagnosis of celiac disease or/and inflammatory bowel diseases
  • Are pregnant or breastfeeding
  • Have prediabetes and diabetes
  • Have had bariatric surgery
  • Are immunocompromised ( e.g., cancer treatment, bone marrow/organ transplant, immune deficiency, or poorly controlled HIV/AIDS)
  • Are unable to provide consent
  • Are hospitalized,
  • Have a history of or current alcohol, drug, or medication abuse (self-reported),
  • Have contraindication to any substance in the investigational product or who are currently enrolled in other interventional trials

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: freeze-dried table grape powder (FTGP)
Drink a daily supplement containing FTGP for 4 weeks
Dietary supplement: freeze-dried table grape powder
48g freeze-dried table grape powder/day for 4 weeks
Placebo Comparator: Placebo
Drink a daily supplement containing a placebo for 4 weeks
Dietary supplement: Placebo
48g placebo/day for 4 weeks

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Hamilton Anxiety Scale -14
Time Frame: baseline (1st), week 4 (2nd) and week 5 (3rd)
HAMA-14 is one of the earliest and most widely used clinical scales for measuring the severity of a patient's anxiety. It has 14 items, each reflecting a cluster of anxiety symptoms. Total range: 0 to 56, with higher scores indicating greater severity of anxiety
baseline (1st), week 4 (2nd) and week 5 (3rd)
17-item of Hamilton Depression Rating Scale
Time Frame: baseline (1st), week 4 (2nd) and week5 (3rd)
HAMD-17 is one of the most widely used clinician-administered scales for measuring the severity of a patient's depression. It has 17 items, each covering symptoms of depression across mood, physical, and cognitive domains. With higher scores indicating greater severity of depression.
baseline (1st), week 4 (2nd) and week5 (3rd)
10-item of Perceived Stress Scale
Time Frame: baseline (1st), week 4 (2nd) and week5 (3rd)
PSS-10 is one of the most widely used psychological instruments for measuring the perception of stress. It has 10 items, each reflecting how unpredictable, uncontrollable, and overloaded respondents find their lives during the past month. Total range: 0 to 40, with higher scores indicating greater perceived stress.
baseline (1st), week 4 (2nd) and week5 (3rd)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Shannon Index of gut microbiota
Time Frame: baseline (1st), week 4 (2nd) and week5 (3rd)
Changes in gut microbiota will be assessed from stool samples using 16S rRNA gene sequencing. Alpha diversity will be calculated using Shannon Index. This measure will characterize whether the intervention alters gut microbial diversity in each subject.
baseline (1st), week 4 (2nd) and week5 (3rd)
Beta diversity of gut microbiota
Time Frame: baseline (1st), week 4 (2nd) and week 5 (3rd)
Changes in gut microbiota will be assessed from stool samples using 16S rRNA gene sequencing. Beta diversity will be calculated using Bray Curtis distance between samples. This measure will characterize whether and how the intervention alters gut microbial communities.
baseline (1st), week 4 (2nd) and week 5 (3rd)
fecal short chain fatty acid
Time Frame: baseline (1st), week 4 (2nd) and week5 (3rd)
fecal short chain fatty acid will be measured by GC-MS
baseline (1st), week 4 (2nd) and week5 (3rd)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Rutgers, The State University of New Jersey

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
California Table Grape Commission

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Guojun Wu, Rutgers, The State University of New Jersey

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 20, 2025

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 24, 2025

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 30, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 1, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 7, 2025

First Posted (Estimated)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 9, 2025

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 15, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 14, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • Pro2025001394

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

IPD might not be shared according to the consent form.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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