Berries, Bugs, and the Blues

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

Official Title
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Blueberries, Gut Microbiota, and Metabolites in Depressed Older Adults - A Pilot Study

Conditions
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Depressive Symptoms

Intervention / Treatment
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* Other: Freeze-dried Blueberry Powder
* Other: Placebo Powder


Participation Criteria
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Eligibility Criteria
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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) 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 Self-reporting type 1 or type 2 diabetes Allergic to intervention or control products Recent use (within the last 3 months) of antibiotics Recent use (within the last 3 months) of pro-biotics 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) 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)

Ages Eligible for Study
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Minimum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Freeze-dried Blueberry Powder<br>Randomized participants will be asked to consume 48 grams of freeze-dried blueberry powder each day for 12 weeks. | Other: Freeze-dried Blueberry Powder<br>* 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.<br>|
| Placebo Comparator: Placebo Powder<br>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. | Other: Placebo Powder<br>* 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.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Depressive Symptom Severity | Severity of depressive symptoms will be measured each week with the Center for Epidemiological Studies Depression Scale (CES-D). Scores range from 0 to 60 points, with higher scores indicating more sever depressive symptoms. | Up to 12 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Abundance microbes | The abundance of microbes that produce short chain fatty acids(e.g., Bifidobacteria, Eubacterium, and Clostridium) will be evaluated by whole genome sequencing | After 12 weeks | 
| Fecal short chain fatty acids | The concentration of short chain fatty acids in feces will be measured using gas chromatography mass spectrometry. | After 12 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Anthocyanins, Fiber, Aging