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NCT Number: NCT07214428

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

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.

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This study is active but is not currently recruiting participants.

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Key information

Conditions

Gut Microbiota Psychological Distress

Age range

18 year–30 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Department of Biochemistry and Microbiology, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey

New Brunswick, New Jersey, 08901, United States

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

freeze-dried table grape powder

Dietary Supplement

48g freeze-dried table grape powder/day for 4 weeks

Placebo

Dietary Supplement

48g placebo/day for 4 weeks

Primary outcomes

  1. 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

  2. 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.

  3. 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.

Secondary outcomes

  1. 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.

  2. 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.

  3. 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

Sponsors and collaborators

Lead sponsor

Rutgers, The State University of New Jersey

Other

Collaborators

  • California Table Grape Commission

Registry information

Official study title

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

Important dates

Study start
2025
Primary completion
2025
Study completion
2026
First posted
Oct 9, 2025
Registry last updated
Jan 15, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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