Investigating the Impact of Probiotics on Wellbeing in a Community

Effects of Probiotic Supplementation on Cognitive Lapses and Gastrointestinal Symptoms in a Non-Clinical Population: A Randomised, Placebo-Controlled Trial

The goal of this clinical trial is to find out whether taking probiotics can improve thinking ability and gut (digestive) symptoms in healthy adults. The study will also explore whether probiotics affect mental health, alcohol cravings, and drinking and eating behaviours.

The main questions it aims to answer are:

• Do probiotics improve everyday thinking, attention, and memory?
• Do probiotics reduce digestion issues or discomfort?
• Do probiotics modulate alcohol cravings?
• Do probiotics improve mood, stress, and anxiety levels?
• Do probiotics influence drinking behaviour?
• Do probiotics influence eating behaviour?

Researchers will compare a probiotic supplement to a placebo (a look-alike product with no active ingredients) to see whether probiotics have real effects. Participants will be randomly assigned to one of these groups, and neither the participants nor the researchers will know who is receiving which treatment during the study.

Participants will:

• Take either a probiotic supplement or a placebo every day for 8 weeks
• Complete online questionnaires about their mood, thinking, eating and drinking behaviours, and digestive health at the start and end of the study
• Provide basic lifestyle and demographic information

This study aims to better understand whether probiotics could be a simple and low-cost way to support cognitive function, digestive health and other wellbeing outcomes in generally healthy adults.

Study Overview

• Status: Completed
• Conditions: This Study Focus Focuses on a Non-clinical Sample of Generally Healthy Adults, and Whether Probiotics Offer Any Holistic Health Benefits
• Intervention / Treatment: Dietary supplement: Placebo Arm; Dietary supplement: Probiotic Arm

• Study Type: Interventional
• Enrollment (Actual): 85
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Loughborough, United Kingdom
    • Loughborough University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Exclusion Criteria:

• Participants under 18 years of age
• Current use of probiotics or prebiotics (in supplements or foods) within the past 4 weeks
• Antibiotic use within the past 4 weeks
• Chronic gastrointestinal disorders (e.g. Irritable Bowel Syndrome, Crohn's disease, etc)
• Major psychiatric conditions diagnosed (e.g., bipolar disorder, schizophrenia, etc)
• Current pregnancy or breastfeeding

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo Group	Dietary supplement: Placebo Arm; The participant will be randomly assigned to receive the placebo, containing no active ingredient/live bacteria
Active Comparator: Probiotic Group	Dietary supplement: Probiotic Arm; The participant will be randomly assigned to receive the probiotic, containing the active ingredient and live bacteria

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
85 non-clinical participants assessed for Everyday Cognitive Failures by Cognitive Failures Questionnaire 2.0	Everyday cognitive functioning will be assessed using the Cognitive Failures Questionnaire 2.0 (CFQ 2.0), a 15-item self-report questionnaire measuring the frequency of cognitive lapses in daily life (e.g., memory, attention, and action errors). Each item is rated on a 5-point scale. Total scores are calculated by summing all item responses, yielding a score ranging from 0 to 60. Performance will be measured as the total CFQ 2.0 score (range 0-60), with higher scores indicating greater frequency of cognitive failures.	From enrollment to the end of the treatment at 8 weeks
85 non-clinical participants assessed for Gastrointestinal Symptoms by Gastrointestinal Symptom Rating Scale	Gastrointestinal symptoms will be assessed using the Gastrointestinal Symptom Rating Scale (GSRS), a 15-item self-report questionnaire evaluating the severity of common gastrointestinal symptoms. Each item is rated on a 7-point Likert scale, with higher scores indicating more severe symptoms. Total scores are calculated by summing all item responses, yielding a score ranging from 15 to 105. Performance will be measured as the total GSRS score (range 15-105), with higher scores indicating greater gastrointestinal symptom severity. Domain scores may also be calculated by averaging relevant items to assess specific symptom clusters.	From enrollment to the end of the treatment at 8 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
85 non-clinical participants assessed for Drinking Behaviour by Loughborough Alcohol Drinking Questionnaire	Drinking behaviour will be assessed using the Loughborough Alcohol Drinking Questionnaire (LoAD-Q), a 33-item self-report questionnaire measuring three dimensions: emotional drinking, external drinking, and restrained drinking. Each item is rated on a 5-point Likert scale (1 = never to 5 = very often). Subscale scores are calculated by summing item responses within each dimension. The emotional drinking subscale (13 items) has a score range of 13 to 65, the external drinking subscale (10 items) ranges from 10 to 50, and the restrained drinking subscale (10 items) ranges from 10 to 50. Performance will be measured as subscale total scores, with higher scores indicating greater levels of emotional, external, and restrained drinking behaviour, respectively.	From enrollment to the end of the treatment at 8 weeks
85 non-clinical participants assessed for Depression, Anxiety, and Stress by Depression Anxiety Stress Scales-12	Mental health symptoms will be assessed using the Depression Anxiety Stress Scales-12 (DASS-12), a 12-item self-report questionnaire measuring symptoms of depression, anxiety, and stress. Each item is rated on a 4-point Likert scale (0-3), yielding a total score ranging from 0 to 36. Performance will be measured as the total DASS-12 score (range 0-36), with higher scores indicating greater psychological distress.	From enrollment to the end of the treatment at 8 weeks
85 non-clinical participants assessed for Alcohol Craving by Penn Alcohol Craving Scale	Alcohol craving will be assessed using the Penn Alcohol Craving Scale (PACS), a 5-item self-report questionnaire measuring frequency, intensity, and duration of alcohol cravings over the past week. Each item is rated on a scale from 0 to 6, yielding a total score ranging from 0 to 30. Performance will be measured as the total PACS score (range 0-30), with higher scores indicating greater alcohol craving severity.	From enrollment to the end of the treatment at 8 weeks

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
85 non-clinical participants assessed for Disordered Eating by Eating Disorder Examination Questionnaire Short Form	Disordered eating behaviours will be assessed using the Eating Disorder Examination Questionnaire Short Form (EDE-QS), a 12-item self-report questionnaire measuring eating disorder psychopathology over the past 7 days. Each item is rated on a 4-point scale (0-3), yielding a total score ranging from 0 to 36. Performance will be measured as the total EDE-QS score (range 0-36), with higher scores indicating greater severity of disordered eating behaviours.	From enrollment to the end of the treatment at 8 weeks

Collaborators and Investigators

• Sponsor: Loughborough University
• Collaborators: Innovate UK

Study record dates

Study Major Dates

• Study Start (Actual): September 28, 2025
• Primary Completion (Actual): February 20, 2026
• Study Completion (Actual): March 1, 2026

Study Registration Dates

• First Submitted: March 21, 2026
• First Submitted That Met QC Criteria: March 26, 2026
• First Posted (Actual): April 1, 2026

Study Record Updates

• Last Update Posted (Actual): April 1, 2026
• Last Update Submitted That Met QC Criteria: March 26, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: 22675

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

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