Coffee Consumption, the Gut Microbiome, and the Microbiota-Gut-Brain Axis

Study Overview
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Brief Summary
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The aim of this study is to investigate the potential of coffee to act as a prebiotic to alter gut microbiota and improve mood, memory and cognitive performance.

Detailed Description
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The aim of this study is to investigate the potential of coffee to act as a prebiotic to alter gut microbiota and improve mood, memory and cognitive performance. Additional gut-brain axis pathways-related parameters such as inflammation, short chain fatty acids and other metabolites production and physiological stress levels will be explored. Moreover, differences between caffeinated and decaffeinated coffee consumption will be investigated to determine whether observed effects are attributed to caffeine or other coffee components. To determine the mechanism of action underlying the beneficial effects of coffee, coffee drinkers abstained from coffee and caffeine for a 2-week washout period following the baseline visit. Coffee drinkers further underwent an intervention in which they consumed either 4 sachets (1.8 grams each) of instant caffeinated or decaffeinated coffee per day for 3 weeks of using a double-blind, randomised, parallel design. Reaction time, socioemotional processing, visual and episodic memory, learning, and an attentional task were administered to measure cognitive performance. Self-report questionnaires on mood, behavior and lifestyle were administered and response to an acute stressor was assessed. Biological samples of saliva, urine, blood, and stool were collected to investigate microbiome-gut-brain-axis signaling.

Official Title
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Coffee Consumption, the Gut Microbiome, and the Microbiota-Gut-Brain Axis

Conditions
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Healthy

Intervention / Treatment
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* Other: Caffeinated coffee
* Other: Decaffeinated coffee


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Be able to give written informed consent. Be between 30 and 50 years of age. Be in generally good health as determined by the investigator. Drink moderate amounts of coffee daily (3-5 cups/day) Exclusion Criteria: Are less than 30 and greater than 50 years of age. Have a significant acute or chronic coexisting illness [cardiovascular, gastrointestinal (GI) [to include functional GI disorders, inflammatory bowel disease, coeliac disease, lactose intolerance, food allergies], immunological, psychiatric [to include formal or as determined by MINI Psychiatric interview, diagnosis of current major depression, anxiety disorder, bipolar spectrum disorder, schizophrenia, other DSM-IV Axis I disorder], neurodevelopmental disorders, immunological, metabolic disorders [to include type I or II diabetes], or any condition which contraindicates, in the investigators judgement, entry to the study, Have a condition or taking a medication that the investigator believes would interfere with the objectives of the study, pose a safety risk or confound the interpretation of the study results; all psychoactive medications [to include anxiolytics, antipsychotics, antidepressants, anticonvulsants, centrally acting corticosteroids and opioid pain relievers), laxatives, enemas, antibiotics, anti-coagulants, over-the counter non-steroidal anti-inflammatories (NSAIDS). Subjects should have a wash-out period of 4 weeks. Be hypertensive. Current prebiotic or probiotic supplement use (a wash-out period of 4 weeks after cessation will allow entry to the study), or habitual consumption of foods deemed by the investigator to be particularly rich in prebiotic fibres or probiotic strains or are vegan. Females who are pregnant or planning a pregnancy, or lactating. Participants who are not fluent in English. Participants who have dyslexia or dyscalculia. Are a current habitual daily smoker. Individuals who, in the opinion of the investigator, are considered to be poor attendees or unlikely for any reason to be able to comply with the trial. Subjects receiving treatment involving experimental drugs. If the subject has been in a recent experimental trial, these must have been completed not less than 30 days prior to this study. Have a malignant disease or any concomitant end-stage organ disease. Have already done a study in the lab in the past 4 years

Ages Eligible for Study
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Minimum Age: 30 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Caffeinated coffee<br>4 sachets (1.8 grams each) of instant, caffeinated coffee | Other: Caffeinated coffee<br>* After 2 weeks of coffee abstinence (washout), participants who were coffee drinkers were randomly allocated to receive either 4 sachets (1.8g each) of caffeinated instant coffee per day for 3 weeks. Participants were blinded to coffee contents.<br>|
| Experimental: Decaffeinated coffee<br>4 sachets (1.8 grams each) of instant, decaffeinated coffee | Other: Decaffeinated coffee<br>* After 2 weeks of coffee abstinence (washout), participants who were coffee drinkers were randomly allocated to receive either 4 sachets (1.8g each) of decaffeinated instant coffee per day for 3 weeks. Participants were blinded to coffee contents.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Microbiota composition and function | Shotgun metagenomics of fecal samples | Differences between groups at baseline, at 2-week coffee abstinence and at 3-week coffee intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Gut microbial metabolites (including Short-Chain fatty acids) | Untargeted metabolomics of fecal samples | Differences between groups at baseline, at 2-week coffee abstinence and at 3-week coffee intervention | 
| Coffee-related metabolites | Targeted metabolomics of coffee-related metabolomics in fecal and urine samples | Differences between groups at baseline, at 2-week coffee abstinence and at 3-week coffee intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Coffee, Microbiome-gut-brain-axis, Prebiotic, Polyphenol, Cognition, Stress, Mood, Behavior, Inflammation, Gut Microbiota, Caffeine