Skip to main content
OpenTrials
Recruiting

NCT Number: NCT05946083

The Brain, the Bug, and the Binge: the Interplay Between Binge Drinking, Gut Microbiota, and Brain Functioning

Adolescence and youth are periods of significant maturational changes which seems to involve greater susceptibility to disruptive events in the brain such as binge drinking (BD). This prevalent pattern of consumption -characterized by repeated alcohol intoxications- is of special concern, as it has been associated with major neurocognitive impairments in the young brain.

Recent studies indicate that alcohol may disrupt the gut microbiota (GM) and that these disruptions may lead to impairments in brain and behavior. Also, interventions with psychobiotics have been shown to result in reductions in alcohol-induced damage and in improvements on cognitive and brain functioning.

Thus, the present proposal will explore the effects of BD on GM. Additionally, a GM intervention with psychobiotics both in-vivo and in-vitro, will determine whether improvements in GM composition/function may lead to reductions of alcohol-induced brain damage in BD-population, a barely unexplored research field with major clinical applications.

Recruiting

Interested in participating?

Request Info

Key information

Conditions

Binge Drinking Alcohol Drinking Alcohol-Related Disorders Behavior Chemically-Induced Disorders Drinking Behavior Mental Disorders Substance-Related Disorders

Age range

18 year–23 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

Psychological Neuroscience Laboratory, Psychology Research Center, University of Minho

Braga, Gualtar, Braga, 4710-057, Portugal

Location status: Recruiting

Location contact

Carina Carbia, PhD

SUB_INVESTIGATOR

Clarisse N. Gonçalves, PhD

CONTACT

[email protected]

Diogo P. Martins, MS

SUB_INVESTIGATOR

Eduardo G. López-Caneda, PhD

CONTACT

[email protected]

(+351) 253 604 223

Natália A. Almeida-Antunes, PhD Student

SUB_INVESTIGATOR

Pedro S. Azevedo, PhD Student

SUB_INVESTIGATOR

Rui S. Rodrigues, PhD Student

SUB_INVESTIGATOR

Sónia S. Sousa, PhD

SUB_INVESTIGATOR

About this study

The present study protocol aims to determine the interaction between alcohol consumption, brain function and gut microbiota through several levels of analysis, including techniques to measure brain activity (i.e., magnetic resonance imaging), paradigms to measure cognitive performance, collection of stool and blood samples, and questionnaires. Additionally, this study will investigate the relationship between alcohol, brain activity and gut microbiota and how this can be modified through our diet. The sample will be composed by a cohort of young college students (18-23 years) from the University of Minho (UM; Braga, Portugal) selected according to their drinking patterns. Eighty-two participants will be recruited from UM: 36 non/low-drinkers and 46 binge drinkers (BDs) matched for age and gender. Recruitment will be carried out through an online survey broadcasted using the institutional email. This survey will include a simple sociodemographic section and items regarding the use of alcohol (Alcohol Use Disorder Identification Test - AUDIT, frequency of alcohol consumption, number of drinks consumed on each day of the past week, speed of drinking, etc.). After sample selection, participants will be submitted to the following steps: (1) clinical interview - addresses questions relating to psychological, medical, personal and family history, including questions related to history of alcohol and drug use and some specific questionnaires relating to substance use, as well as those related to physical and psychological symptoms, and personality; (2) neuroimaging assessment - will consist of a structural and functional magnetic resonance imaging (fMRI) at the Hospital de Guimarães (Portugal), while performing different cognitive tasks; (3) evaluation of some microorganisms residing in the gut and certain inflammatory markers - each participant will be asked to collect stool and blood samples; (4) evaluation of the potential of an intervention with psychobiotics.

Thus, this protocol involves the following phases:

  • pre-intervention, consisting of the assessment of the variables of interest to the study by means of a clinical interview, neuropsychological testing, collection of stool and blood samples, and MRI recordings.
  • intervention (only for BDs), consisting of taking a prebiotic for 6 weeks. Depending on the group to which they will be allocated, the participant will take one of two types of fiber: a fiber with benefits for intestinal bacteria (inulin) or a similar fiber with no specific benefits for the intestinal microbiome (maltodextrin). Each participant will not know which group they belong to in order not to bias the results of the study according to scientific standards.
  • post-intervention, which will consist in the re-assessment of the variables previously assessed in the pre-intervention phase.
  • follow-up, consisting of the assessment and monitoring of levels of alcohol consumption and craving during the 3 months following the intervention phase.

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

  • College students whose native language is Portuguese;
  • Age 18-23 years;
  • Binge Drinkers: report (i) drinking 4 (for women)/5 (for men) or more drinks on one occasion at least once a month, (ii) drinking at a speed of at least two drinks per hour during these episodes (which brings blood alcohol concentration to 0.08 g/dL or above), and (iii) having an AUDIT score < 20.
  • Non/Low-Drinkers: report (i) never drinking 4/5 or more drinks on one occasion and (ii) having an AUDIT score ≤ 4.

Exclusion criteria

  • Use of illicit drugs as determined by the Drug Use Disorders Identification Test (DUDIT);
  • Alcohol abuse (i.e., AUDIT ≥ 20);
  • Personal history of psychopathological disorders (according to DSM-V criteria);
  • History of traumatic brain injury or neurological disorder;
  • Family history (mother/father) of alcoholism diagnosis of substance abuse;
  • Occurrence of one or more episodes of loss of consciousness for more than 30 minutes;
  • Non-corrected sensory deficits;
  • Diagnosis of any gut disease/problems or other medical conditions: inflammatory bowel disease, irritable bowel syndrome, Crohn's Disease, celiac disease, lactose intolerance, autoimmune disease;
  • Consumption of medical drugs with psychoactive effects (e.g., antidepressants, anxiolytics or benzodiazepines) during the 4 weeks prior to the experiment;
  • Use of any of the following drugs in the last 4 weeks: laxatives, antibiotics, anticoagulants, non-steroidal anti-inflammatory drugs, analgesics, corticosteroids;
  • No type of metal object implanted in the body, especially in the head (orthodontic appliances are not excluded).

Treatment and study plan

Inulin Intervention

Dietary Supplement

For 6 weeks, 23 binge drinkers will be given a daily dose (divided into three times a day) of 15g of a dietary fiber with benefits for intestinal bacteria (inulin).

Maltodextrin Intervention

Dietary Supplement

For 6 weeks, 23 binge drinkers will be given a daily dose (divided into three times a day) of 15g of dietary fiber with no specific benefits for the intestinal microbiome (maltodextrin).

Primary outcomes

  1. Fecal Microbiota - Species Richness

    Time frame: At baseline (pre-intervention)

    Faecal samples will be collected from all participants for microbiota α-diversity analysis by 16S rRNA metagenomics (Illumina sequencing). The Chao1 Index will be used as an estimator of nonparametric microbial species richness in each sample.

  2. Fecal Microbiota - Species Richness

    Time frame: Immediately post-intervention.

    Faecal samples will be collected only from binge drinkers subjected to the intervention for microbiota α-diversity analysis by 16S rRNA metagenomics (Illumina sequencing). The Chao1 Index will be used as an estimator of nonparametric microbial species richness in each sample.

  3. Fecal Microbiota - Species Diversity

    Time frame: At baseline (pre-intervention)

    Faecal samples will be collected from all participants for microbiota α-diversity analysis by 16S rRNA metagenomics (Illumina sequencing). The Shannon Diversity Index (metric combining richness and evenness, with equal weighting given to abundant and rare species) and the Simpson Diversity Index (metric of richness and evenness, in which more weighting is given to abundant species) will be used.

  4. Fecal Microbiota - Species Diversity

    Time frame: Immediately post-intervention

    Faecal samples will be collected only from binge drinkers subjected to the intervention for microbiota α-diversity analysis by 16S rRNA metagenomics (Illumina sequencing). The Shannon Diversity Index (metric combining richness and evenness, with equal weighting given to abundant and rare species) and the Simpson Diversity Index (metric of richness and evenness, in which more weighting is given to abundant species) will be used.

  5. Fecal Microbiota - Quantification of SCFAs levels

    Time frame: At baseline (pre-intervention)

    The concentration of short-chain fatty acids (SCFAs) present in each collected faecal sample shall be quantified by High Performance Liquid Chromatography (HPLC).

  6. Fecal Microbiota - Quantification of SCFAs levels

    Time frame: Immediately post-intervention.

    The concentration of SCFAs present in each collected faecal sample shall be quantified by HPLC.

Secondary outcomes

  1. Alcohol Consumption - Drinking pattern

    Time frame: Immediately post-intervention

    The AUDIT will be administered to characterize the drinking pattern of the participants. AUDIT scores ≤ 4 reveal low risk of alcohol use; scores between 5 and 20 represent excessive alcohol consumption; and scores ≥ 20 indicate very high risk for alcohol dependence and warrant further diagnostic evaluation for alcohol dependence.

  2. Alcohol Consumption - Drinking pattern

    Time frame: 3 months post-intervention

    The AUDIT will be administered to characterize the drinking pattern of the participants. AUDIT scores ≤ 4 reveal low risk of alcohol use; scores between 5 and 20 represent excessive alcohol consumption; and scores ≥ 20 indicate very high risk for alcohol dependence and warrant further diagnostic evaluation for alcohol dependence.

  3. Alcohol Craving - Short-term acute craving

    Time frame: Immediately post-intervention

    Short-term alcohol craving levels will be assessed using the ACQ-SF-R at the present moment. Total minimum score: 1 (low level of alcohol craving); Total maximum score: 7 (high level of alcohol craving).

  4. Alcohol Craving - Short-term acute craving

    Time frame: 3 months post-intervention

    Short-term alcohol craving levels will be assessed using the ACQ-SF-R at the present moment. Total minimum score: 1 (low level of alcohol craving); Total maximum score: 7 (high level of alcohol craving).

  5. Neuropsychological Evaluation - Memory

    Time frame: At baseline (pre-intervention)

    The Delayed Matching to Sample (DMS) from Cambridge Neuropsychological Test Automated Battery (CANTAB) will be used to assess both simultaneous visual matching ability and short-term visual recognition memory, for non-verbalisable patterns.

  6. Neuropsychological Evaluation - Memory

    Time frame: Immediately post-intervention

    The Delayed Matching to Sample (DMS) from Cambridge Neuropsychological Test Automated Battery (CANTAB) will be used to assess both simultaneous visual matching ability and short-term visual recognition memory, for non-verbalisable patterns.

  7. Neuropsychological Evaluation - Emotion and Social Cognition

    Time frame: At baseline (pre-intervention)

    The Emotion Recognition Task (ERT) from CANTAB will measure the ability to identify six basic emotions (sadness, happiness, fear, anger, disgust, and surprise) in facial expressions along a continuum of expression magnitude.

  8. Neuropsychological Evaluation - Emotion and Social Cognition

    Time frame: Immediately post-intervention

    The Emotion Recognition Task (ERT) from CANTAB will measure the ability to identify six basic emotions (sadness, happiness, fear, anger, disgust, and surprise) in facial expressions along a continuum of expression magnitude.

  9. Neuropsychological Evaluation - Executive Function

    Time frame: At baseline (pre-intervention)

    The performance of the cognitive domain comprising high-level thinking and decision-making will be assessed through CANTAB, namely the Cambridge Gambling Task (CGT, to assess decision-making and risk behaviour outside a learning context), Intra-Extra Dimensional Set Shift (IED, to assess cognitive flexibility), Spatial Working Memory (SWM, to identify working memory strategies and errors) and Stop Signal Task (SST, to measure response inhibition/impulse control).

  10. Neuropsychological Evaluation - Executive Function

    Time frame: Immediately post-intervention

    The performance of the cognitive domain comprising high-level thinking and decision-making will be assessed through CANTAB, namely the Cambridge Gambling Task (CGT, to assess decision-making and risk behaviour outside a learning context), Intra-Extra Dimensional Set Shift (IED, to assess cognitive flexibility), Spatial Working Memory (SWM, to identify working memory strategies and errors) and Stop Signal Task (SST, to measure response inhibition/impulse control).

  11. Alcohol Cue Reactivity - Emotional measures

    Time frame: At baseline (pre-intervention)

    The reactivity to alcoholic cues will be assessed using the Alcohol Cue Reactivity (ACR) task. The full task includes a total of 80 trials with 40 alcoholic and 40 non-alcoholic images obtained from the Amsterdam Beverage Picture Set. The emotional responses for each image in terms of valence and arousal task, will be registered using the Self-Assessment Manikin (valence: from 1 = "very unpleasant" to 9 ="very pleasant"; arousal: from 1 = "not arousing" to 9 = "highly arousing") during the ACR task.

  12. Alcohol Cue Reactivity - Emotional measures

    Time frame: Immediately post-intervention.

    The reactivity to alcoholic cues will be assessed using the ACR task. The full task includes a total of 80 trials with 40 alcoholic and 40 non-alcoholic images obtained from the Amsterdam Beverage Picture Set. The emotional responses for each image in terms of valence and arousal task, will be registered using the Self-Assessment Manikin (valence: from 1 = "very unpleasant" to 9 ="very pleasant"; arousal: from 1 = "not arousing" to 9 = "highly arousing") during the ACR task.

  13. Memory Inhibition Performance

    Time frame: At baseline (pre-intervention)

    Memory Inhibition (MI), specifically alcohol-related MI, will be assessed using the Think/No-Think Alcohol (TNTA) task. Percentage of correct responses (for Think, No-Think and Baseline items) in the TNTA task will be computed according to the following formula: ((number of correctly recalled items)/(number of previously learned items))×100. Correct responses correspond to the items learned during the learning phase and correctly recalled during the memory test phase.

  14. Memory Inhibition Performance

    Time frame: Immediately post-intervention.

    MI, specifically alcohol-related MI, will be assessed using the TNTA task. Percentage of correct responses (for Think, No-Think and Baseline items) in the TNTA task will be computed according to the following formula: ((number of correctly recalled items)/(number of previously learned items))×100. Correct responses correspond to the items learned during the learning phase and correctly recalled during the memory test phase.

  15. Ability of Emotional Recognition

    Time frame: At baseline (pre-intervention)

    Emotional recognition capacity will be assessed through the Emotion Discrimination (ED) task. ED assesses the brain's preconscious and conscious responses to emotional faces. The complete task includes a total of 120 images of human faces (60 men and 60 women), showing the main negative emotions: angry, sadness and fear.

  16. Ability of Emotional Recognition

    Time frame: Immediately post-intervention.

    Emotional recognition capacity will be assessed through the ED task. ED assesses the brain's preconscious and conscious responses to emotional faces. The complete task includes a total of 120 images of human faces (60 men and 60 women), showing the main negative emotions: angry, sadness and fear.

  17. Blood samples - Presence of Inflammatory Markers

    Time frame: At baseline (pre-intervention)

    Blood samples will be collected from all participants. The presence and abundance of the following cytokines will be analyzed: Tumour Necrosis Factor α (TNF-α) and Interleukins (IL-1β, IL-6, IL-10).

  18. Blood samples - Presence of Inflammatory Markers

    Time frame: Immediately post-intervention.

    Blood samples will be collected only from binge drinkers subjected to the intervention. The presence and abundance of the following cytokines will be analyzed: Tumour Necrosis Factor α (TNF-α) and Interleukins (IL-1β, IL-6, IL-10).

  19. Neurofunctional level - Think/No-Think Alcohol (TNTA) Task

    Time frame: At baseline (pre-intervention)

    The TNTA task assesses memory inhibition mechanisms in alcohol-related contexts. It involves three phases - Learning, Think/No-Think and Memory Test - during which participants memorise pairs of images (human faces with a neutral expression and alcoholic/non-alcoholic beverages) and are subsequently instructed to actively recall or suppress these associations.

  20. Neurofunctional level - Think/No-Think Alcohol (TNTA) Task

    Time frame: Immediately post-intervention

    The TNTA task assesses memory inhibition mechanisms in alcohol-related contexts. It involves three phases - Learning, Think/No-Think and Memory Test - during which participants memorise pairs of images (human faces with a neutral expression and alcoholic/non-alcoholic beverages) and are subsequently instructed to actively recall or suppress these associations.

  21. Neurofunctional level - Emotional Face Matching (EFM) Task

    Time frame: At baseline (pre-intervention)

    The EFM task assesses emotional recognition ability and pre-conscious and conscious neural responses to emotional faces and geometric forms. During each trial, participants view three emotional faces or shapes (one on top and two on the bottom, in a triangular configuration) and are instructed to identify the emotion/shape at the top of the screen and match it with the corresponding one at the bottom using handheld response buttons.

  22. Neurofunctional level - Emotional Face Matching (EFM) Task

    Time frame: Immediately post-intervention

    The EFM task assesses emotional recognition ability and pre-conscious and conscious neural responses to emotional faces and geometric forms. During each trial, participants view three emotional faces or shapes (one on top and two on the bottom, in a triangular configuration) and are instructed to identify the emotion/shape at the top of the screen and match it with the corresponding one at the bottom using handheld response buttons.

  23. Neurofunctional level - Alcohol Cue Reactivity (ACR) Task

    Time frame: At baseline (pre-intervention)

    The ACR task assesses the emotional and attentional response to alcoholic stimuli. Participants are shown images of alcoholic and non-alcoholic drinks, interspersed with oddball blocks containing neutral objects, to which they must respond by pressing a button. After viewing all images, participants are asked to rate their emotional responses to the alcoholic or non-alcoholic beverage images in terms of valence, arousal, and desire.

  24. Neurofunctional level - Alcohol Cue Reactivity (ACR) Task

    Time frame: Immediately post-intervention

    The ACR task assesses the emotional and attentional response to alcoholic stimuli. Participants are shown images of alcoholic and non-alcoholic drinks, interspersed with oddball blocks containing neutral objects, to which they must respond by pressing a button. After viewing all images, participants are asked to rate their emotional responses to the alcoholic or non-alcoholic beverage images in terms of valence, arousal, and desire.

Study contacts

Contact information is provided by the study sponsor or research team.

Clarisse N. Gonçalves, PhD

CONTACT

[email protected]

Eduardo G. López-Caneda, PhD

CONTACT

[email protected]

(+351) 253 604 223

Sponsors and collaborators

Lead sponsor

University of Minho

Other

Collaborators

  • Foundation for Science and Technology, Portugal

Registry information

Official study title

The Brain, the Bug, and the Binge: a Double-blind, Randomized Controlled Trial Investigating the Interplay Between Binge Drinking, Gut Microbiota and Brain Functioning

Important dates

Study start
2023
Primary completion
2025
Study completion
2025
First posted
Jul 14, 2023
Registry last updated
Jul 16, 2025

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.

Related clinical trials

Published trials that share one or more normalized conditions with this study.