Berries, Bugs, and the Blues
August 19, 2025 updated by: Courtney Millar, Hebrew SeniorLife
Blueberries, Gut Microbiota, and Metabolites in Depressed Older Adults - A Pilot Study
This study aims to investigate the impact of daily freeze-dried blueberry powder consumption on the gut microbiota, fecal short chain fatty acids, and depressive symptom severity in 40older, sedentary adults with depressive symptoms.
Study Overview
Status
Completed
Conditions
Intervention / Treatment
Detailed Description
This study is an ancillary project to a currently funded randomized, placebo-controlled 12-week intervention in older, sedentary adults with depressive symptoms (IRB# Pro00064749). This specific project proposes distinct aims to the trial by gathering preliminary data on the synergistic impact of dietary fiber and anthocyanins (via freeze-dried blueberry powder) on the gut-microbiota, gut-derived metabolites, and depressive symptoms in older adults.
Participants will then be randomized to consume either 48 g of freeze-dried blueberry powder (~600 mg of anthocyanins and ~8 g of fiber) or 48 g of a nutritionally matched placebo powder (devoid of anthocyanins and fiber) each day for a total of 12 weeks.
At baseline, participants will be undergo assessments for depressive symptom severity and provide a fecal sample for gut microbiota and short chain fatty acid measurement. After 4, 8, and 12 weeks of consuming the powder there will be study visits that assess depressive symptom severity. Additionally, a final fecal sample will be taken after 12 weeks of the intervention.
Study Type
Interventional
Enrollment (Actual)
20
Phase
- 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 Locations
-
-
Massachusetts
-
Roslindale, Massachusetts, United States, 02131
- Hebrew Rehabilitation Center
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-
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
Ages Eligible for Study
- Older Adult
Accepts Healthy Volunteers
No
Description
Inclusion Criteria:
- Men and women aged ≥65 years
- Self-reporting ≥ 8 hours of sitting per/day (e.g., sedentary behavior)
- Depressive symptoms (defined as ≥4 and <16 points on the center for epidemiological studies depression-scale
Exclusion Criteria:
- Unwilling to follow the study protocol
- A median daily step count >7,500 steps per day (as measured by the ActiGraph), or per discretion of the PI
- Cognitive impairment (defined as Montreal Cognitive Assessment, MoCA <22 points)
- Self-reporting a history of inflammatory bowel disease/syndrome, major depression, bipolar, schizophrenia, or other psychotic disorders, or per discretion of the PI
- Self-reporting type 1 or type 2 diabetes
- Allergic to intervention or control products
- Recent use (within the last 3 months) of antibiotics, or per discretion of the PI
- Recent use (within the last 3 months) of pro-biotics, or per discretion of the PI
- Current substance use disorder (Drug Abuse Screening Test, DAST-10>2 points)
- Current alcohol use disorder (Alcohol Use Disorders Identification Test - Consumption, AUDIT-C≥4 points)
- Unstable anti-depressant use (e.g., change in medication within last 3-6 months), or per discretion of the PI
- Current homicidal or suicidal ideation (assessed via the P4 Suicidality Screener)
- Current psychosis (via the Psychosis and Hallucinations Questionnaire, PHQ>12 points)
- Manic symptoms (assessed by the Mood Disorder Questionnaire, MDQ >5 points)
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: Other
- Allocation: Randomized
- Interventional Model: Parallel Assignment
- Masking: Triple
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
|---|---|
|
Experimental: Freeze-dried Blueberry Powder
Randomized participants will be asked to consume 48 grams of freeze-dried blueberry powder each day for 12 weeks.
|
Participants will be asked to consume 48 grams of freeze-dried blueberry powder (~ equivalent to 2 cups of fresh blueberries) daily for 12 weeks.
Participants will be asked to save any powder packet wrappers as a means to measure compliance.
They will also be instructed to avoid consumption of foods/beverages that are high in anthocyanins and/or fiber.
|
|
Placebo Comparator: Placebo Powder
Randomized participants will be asked to consume 48 grams of a nutritionally matched placebo powder devoid of fiber and anthocyanins each day for 12 weeks.
|
Participants will be asked to consume 48 grams of a nutritionally matched placebo powder (that does not contain fiber or anthocyanins) daily for 12 weeks.
Participants will be asked to save any powder packet wrappers as a means to measure compliance.
They will also be instructed to avoid consumption of foods/beverages that are high in anthocyanins and/or fiber.
|
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
Depressive Symptom Severity
Time Frame: Change between baseline and 12 weeks
|
Severity of depressive symptoms will be measured before and after the intervention with the Center for Epidemiological Studies Depression Scale-Revised (CESD-R).
Scores range from 0 to 60 points, with higher scores indicating more sever depressive symptoms.
|
Change between baseline and 12 weeks
|
Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
Abundance Microbes
Time Frame: Change between baseline and 12 week follow-up
|
The abundance of the top 20 most prevalent microbes in our that produce short chain fatty acids (e.g., Bifidobacteria, Eubacterium, and Clostridium) will be evaluated by whole genome sequencing
|
Change between baseline and 12 week follow-up
|
|
Fecal Short Chain Fatty Acids (i.e., Butyrate)
Time Frame: Percent change between baseline and 12 week follow-up
|
The relative abundance of short chain fatty acids (i.e., butyrate ) in feces will be measured using liquid chromatography mass spectrometry.
|
Percent change between baseline and 12 week follow-up
|
Collaborators and Investigators
This is where you will find people and organizations involved with this study.
Sponsor
Investigators
- Principal Investigator: Courtney Millar, PhD, Hebrew SeniorLife, Marcus Institute of Aging, Harvard Medical Schools
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)
April 5, 2023
Primary Completion (Actual)
July 16, 2024
Study Completion (Actual)
July 16, 2024
Study Registration Dates
First Submitted
April 5, 2023
First Submitted That Met QC Criteria
April 5, 2023
First Posted (Actual)
April 18, 2023
Study Record Updates
Last Update Posted (Actual)
August 22, 2025
Last Update Submitted That Met QC Criteria
August 19, 2025
Last Verified
August 1, 2025
More Information
Terms related to this study
Keywords
Additional Relevant MeSH Terms
Other Study ID Numbers
- Pro00068528
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
YES
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.