The GLUCID Study: Effect of Alcohol Reduction and Probiotic Interventions on Cognition and Brain Glucose Metabolism in Normal Aging Adults Who Are High-Risk Alcohol Drinkers

Effect of Alcohol Reduction and Probiotic Interventions on Cognition and Brain Glucose Metabolism in Normal Aging Adults Who Are High-Risk Alcohol Drinkers

The goal of this pilot study is to explore a combination of two interventions: (1) a behavioral alcohol-reduction intervention using motivational interviewing, and (2) a blinded probiotic microbiome or placebo intervention. The study examines whether these interventions improve cognitive and neurophysiological function, including brain metabolism, in older adults who are high-risk alcohol drinkers.

Study Overview

• Status: Recruiting
• Conditions: Alcohol Drinking; Aging
• Intervention / Treatment: Dietary supplement: Visbiome; Behavioral: Motivational Interviewing; Other: Placebo

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Teddy Salan, PhD; Phone Number: 305-243-9228; Email: txs785@med.miami.edu

Study Locations

• United States
  • Florida
    • Miami, Florida, United States, 33136
      • Recruiting
      • University of Miami
      • Contact: Teddy Salan, PhD; Phone Number: 305-243-9228; Email: txs785@med.miami.edu
      • Principal Investigator: Teddy Salan, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Between 65 and 84 years of age
• English speaking
• Able to provide valid informed consent, understand requirement and risk/benefits of the study and comply with study protocol
• Heavy drinker defined as >14 alcoholic drinks/week for men and >7 drinks/week for women
• Interested in reducing their alcohol consumption

Exclusion Criteria:

• BMI ≥ 35
• Fasting Glucose > 125 mg/dL
• Current or previously diagnosed with Type 1 or 2 Diabetes
• Requires the use of insulin and/or other glucose lowering agents
• Unable to fast for 12 hours
• Past serious alcohol withdrawal symptoms
• MRI Contraindications (e.g., certain devices and implants, claustrophobic)
• Diagnosed with a neurodegenerative disease (e.g., Alzheimer's Disease)
• Diagnosed with a psychotic disorder
• Current substance dependence diagnosis (except for mild or moderate alcohol)
• Consumption of over 300 drinks in the past 30 days
• Current probiotic use or recent probiotic use within the past 30 days
• Current antibiotic use or recent antibiotic use within the past 30 days
• In active cancer treatment and/or have advanced cancer
• Taking daily steroids and/or immunosuppressants
• Lifetime organ or bone marrow transplant; primary immunodeficiency (e.g., DiGeorge syndrome or Wiskott-Aldrich syndrome) or transplant recipient or prescribed immunosuppressant medications
• PI's discretion

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Motivational Interviewing + Probiotic; Participants in this arm will be given a brief motivational interview to promote drinking reduction. During the 30-day intervention, participants will receive an active probiotic supplement 900 billion colony forming units (CFU), once daily.	Dietary supplement: Visbiome; Participants will receive 900 billion Colony Forming Units (CFU) once daily for 30 days; Behavioral: Motivational Interviewing; Participants will receive one counseling session at baseline via video call, lasting up to 30 minutes
Placebo Comparator: Motivational Interviewing + Placebo; Participants in this arm will be given a brief motivational interview to promote drinking reduction. During the 30-day intervention, participants will receive a placebo supplement once daily.	Behavioral: Motivational Interviewing; Participants will receive one counseling session at baseline via video call, lasting up to 30 minutes; Other: Placebo; Participants will receive a standard placebo designed to resemble the probiotic once daily for 30 days

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Total Cognition Composite score	Cognitive performance will be assessed using the NIH Toolbox Cognition Battery v3 to measure the Total Cognition Composite score at two time-points and examined for change within subjects.	Baseline, 30 days
Change in Brain Metabolism	Brain metabolism will be assessed using magnetic resonance spectroscopy (MRS) to quantify glucose uptake.	Baseline, 30 days

Collaborators and Investigators

• Sponsor: University of Miami
• Collaborators: Exegi Pharma
• Investigators: Principal Investigator: Teddy Salan, PhD, University of Miami

Study record dates

Study Major Dates

• Study Start (Actual): February 26, 2026
• Primary Completion (Estimated): April 30, 2027
• Study Completion (Estimated): April 30, 2027

Study Registration Dates

• First Submitted: January 22, 2026
• First Submitted That Met QC Criteria: February 9, 2026
• First Posted (Actual): February 17, 2026

Study Record Updates

• Last Update Posted (Actual): March 4, 2026
• Last Update Submitted That Met QC Criteria: March 3, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Drinking Behavior; Behavior; Alcohol Drinking; Health Services; Health Care Facilities Workforce and Services; Behavioral Disciplines and Activities; Directive Counseling; Counseling; Mental Health Services; Motivational Interviewing
• Other Study ID Numbers: 20250474

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No