Effects of Probiotic Supplementation on Stress and Anxiety in Students
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Probiotics, Placebo.
- Who it may be relevant to
- Registry conditions: Stress, Anxiety, Sleep, Gastro-intestinal Symptoms in Healthy Subjects. Basic parameters: 18 years — 40 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Poland
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
The Efficacy of Probiotic Supplementation in Reducing Stress and Anxiety: A Randomized, Placebo-Controlled Study in Healthy Students During the Examination Period
Overview
This randomized, double-blind, placebo-controlled study evaluates the efficacy and safety of an 8-week probiotic supplementation (Lactobacillus plantarum LP140 and Bifidobacterium breve BB010 in total daily dose 1 × 10¹⁰ CFU or matching placebo) in reducing perceived stress and anxiety, and improvement related psychological parameters in healthy university students during the examination period. The primary outcome is the change in Perceived Stress Scale (PSS-10) score at week 5 and week 8 of interevention compared to placebo. The secondary outcomes are the changes in DASS-21 subscales (Stress, Anxiety, Depression), State-Trait Anxiety Inventory - State version scale (STAI-S), Sense of Coherence Scale (SOC-29), Pittsburgh Sleep Quality Index (PSQI), self-reported gastrointestinal symptoms (Likert scale) and incidence of adverse events during the 8-week lasting interventional study.
Detailed description
The gut-brain axis enables bidirectional communication between the gastrointestinal tract and the central nervous system. Emerging evidence suggests that selected probiotic strains (psychobiotics) may modulate stress responses and emotional regulation. University examination periods constitute a predictable model of transient psychological stress in otherwise healthy individuals.
This study investigates whether daily supplementation with a probiotic combination of Lactobacillus plantarum LP140 and Bifidobacterium breve BB010 reduces perceived stress and improves related psychological parameters in healthy students exposed to exam-related stress. Two hundred male and female students aged 18-40 years with at least moderate stress and mild anxiety, but without clinical depression, will be enrolled at the Medical University of Lublin, Poland. After providing written informed consent and confirming eligibility criteria, participants will be randomized in a 1:1 ratio to receive either a probiotic formulation containing Lactobacillus plantarum LP140 and Bifidobacterium breve BB010 (total daily dose of 1 × 10¹⁰ colony-forming units) or a matching placebo.
The investigational product and placebo will be identical in appearance and administered orally once daily (two capsules) for 8 weeks. Randomization will be computer-generated, and both participants and investigators will remain blinded to treatment allocation throughout the study. The intervention will begin approximately six weeks before the first scheduled academic examination. Study assessments will be conducted at baseline, at week 5 (approximately one week before the first examination), and at week 8 (±3 days before a subsequent examination). Psychological and functional parameters will be collected using validated self-report instruments administered electronically, with selected assessments performed during on-site visits. Participants will be asked to maintain their usual diet, physical activity, and caffeine intake during the study period. Safety and tolerability will be monitored throughout the intervention, and adverse events will be recorded using an electronic reporting system with daily reminders.
The study is powered to detect clinically meaningful differences between groups in perceived stress levels and will be analyzed using appropriate covariance-based statistical models adjusted for baseline values and relevant covariates. All participant data will be coded to ensure confidentiality and handled in accordance with applicable data protection regulations.
Interventions
- Dietary supplement Probiotics
Lactobacillus plantarum LP140 and Bifidobacterium breve BB010 - Other Placebo
Maltodextrin
Primary outcome measures
- Change in perceived stress score [Time frame: Change in total perceived stress score from baseline to week 5 and to week 8 (±3 days) compared to placebo]
Secondary outcome measures (6)
- Change in stress, anxiety and depression scores [Time frame: Change in DASS-21 Stress, Anxiety, and Depression subscale scores from baseline to week 5 and week 8 (±3 days) compared to placebo.]
- Change in sleep quality score [Time frame: Change in Pittsburgh Sleep Quality Index (PSQI) global score from baseline to week 5 and week 8 (±3 days) compared to placebo.]
- Change in sense of coherence score [Time frame: Change in Sense of Coherence Scale - 29 Items (SOC-29) total score from baseline to week 5 and week 8 (±3 days) compared to placebo.]
- Change in state anxiety score [Time frame: Change in State-Trait Anxiety Inventory - State version (STAI-S) total score from baseline to week 8 compared to placebo.]
- Change in severity of gastro-intestinal symptoms [Time frame: Change from baseline in gastro-intestinal severity score at Week 5 and Week 8 compared to placebo]
- Incidence of treatment-emergent adverse events (Safety and Tolerability) [Time frame: From baseline through the 8-week intervention period.]
Eligibility criteria
Inclusion criteria
- Male or female students aged 18-40 years
- At least moderate stress (DASS-21 Stress score ≥10)
- Mild anxiety (DASS-21 Anxiety score 6-13)
- No clinical depression (DASS-21 Depression score ≤9)
- Willingness to maintain usual diet, physical activity, and intake of caffeinated beverages during the study
- Written informed consent
Exclusion criteria
- Irritable bowel syndrome (Rome IV criteria) or any chronic intestinal disease (including celiac disease)
- Known food allergies, immunodeficiency disorders, or immunosuppressive treatment
- Antibiotic use within 4 weeks prior to screening
- Any psychiatric illness within the past 5 years
- Any malignant disease or autoimmune or allergic diseases (e.g., atopic dermatitis, asthma)
- Use of systemic psychotropic medications or steroids; use of topical corticosteroid creams within 4 weeks prior to screening
- Pregnancy, breastfeeding, or plans to become pregnant during the study
- Probiotic or prebiotic consumption or planned dietary changes within 4 weeks prior to screening
- Heavy caffeine consumption (>4 cups of 300 mL coffee per day)
- Drug or alcohol addiction or regular use of recreational drugs
- Smoking more than 10 cigarettes per day
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- Randomized
- Model
- Parallel assignment
- Masking
- Quadruple blind
- Primary purpose
- Prevention
Study locations
Poland · 1 center
- University of Lublin, Faculty of Health Sciences — Lublin
Identifiers
NCT: NCT07470645 · CT/NB/180/2025/PR-MS