An interventional study of Probiotics and Placebo in Stress, Anxiety and Sleep, sponsored by Nordic Biotic Sp. z o.o.. Recruiting at 1 site in Poland. Open to participants aged 18 Years to 40 Years. Per ClinicalTrials.gov, last updated 2026-09-25.
Sponsored by Nordic Biotic Sp. z o.o. · Not applicable, Interventional, and Prevention
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.
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.
7,207 studies on the registry are indexed under Anxiety Disorders; 1,682 are open to participants now.
This study's planned enrollment of 200 is above the median of 80 across 6,062 interventional studies indexed under Anxiety Disorders.
Browse Anxiety Disorders studies →Nordic Biotic Sp. z o.o. is the lead sponsor of 7 studies on the registry; 1 is open to participants now.
Compared within Anxiety Disorders, the registry's first condition term, which may not be this study's main condition. Counted across the registry records on this site, refreshed daily. How we classify →
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Two capsules containing Lactobacillus plantarum LP140 and Bifidobacterium breve BB010 will be administered orally once daily (total daily dose of 1 × 10¹⁰ colony-forming units) for 8 weeks.
Dietary Supplement: Probiotics
Maltodextrin will be used as a placebo. The placebo capsules will be identical in appearance to the probiotic capsules and will be administered orally once daily (two capsules) for 8 weeks.
Other: Placebo
Lactobacillus plantarum LP140 and Bifidobacterium breve BB010
Maltodextrin
Change in perceived stress score
Perceived stress will be assessed using the 10-Item Perceived Stress Scale (PSS-10), a validated questionnaire measuring the degree to which situations in one's life are appraised as stressful. The total score ranges from 0 to 40, with higher scores indicating higher perceived stress levels (worse outcome). Changes in the total score from baseline will be analyzed to evaluate the effect of probiotic supplementation.
Time frame: Change in total perceived stress score from baseline to week 5 and to week 8 (±3 days) compared to placebo
Change in stress, anxiety and depression scores
Stress, anxiety, and depression will be assessed using the Depression Anxiety Stress Scales - 21 Items (DASS-21). The DASS-21 consists of three subscales (Depression, Anxiety, and Stress), each including 7 items. Scores for each subscale range from 0 to 42 after standard score multiplication, with higher scores indicating greater symptom severity (worse outcome). Changes in the Stress, Anxiety, and Depression subscale scores from baseline will be analyzed to evaluate the effect of probiotic supplementation.
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
Sleep quality will be assessed using the Pittsburgh Sleep Quality Index (PSQI), a validated questionnaire measuring sleep quality over the previous month. The global PSQI score ranges from 0 to 21, with higher scores indicating poorer sleep quality (worse outcome). Changes in the PSQI global score from baseline will be analyzed to evaluate the effect of probiotic supplementation.
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
Sense of coherence will be assessed using the Sense of Coherence Scale - 29 Items (SOC-29), a validated questionnaire measuring psychological resilience and the ability to cope with stress. The total score ranges from 29 to 203, with higher scores indicating a stronger sense of coherence (better outcome). Changes in the SOC-29 total score from baseline will be analyzed to evaluate the effect of probiotic supplementation.
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
State anxiety will be assessed using the State-Trait Anxiety Inventory - State version (STAI-S), a validated questionnaire measuring the current level of anxiety. The STAI-S total score ranges from 20 to 80, with higher scores indicating higher levels of anxiety (worse outcome). Changes in the STAI-S total score from baseline will be analyzed to evaluate the effect of probiotic supplementation.
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
The severitty of gastro-intestinal symptoms will be assessed with the use of 4-point Likert scale (0 - no symptom, 1 - weak, 2 - moderate, 4 - severe). The following symptoms will be assessed: abdominal pain, flatulence, nausea.
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)
Safety and tolerability will be assessed by monitoring the incidence of adverse events throughout the study. Adverse events will be self-reported by participants using an electronic reporting platform, which provides daily reminders for study product intake and allows participants to record any symptoms or adverse events experienced during the study period.
Time frame: From baseline through the 8-week intervention period.
Plan to share: No
No publications or documents are linked to this record.
Ran from Apr 2026 to primary completion in Jul 2026, 2 months.
Of 102 industry-sponsored interventional studies with no phase under Anxiety Disorders, half reached primary completion within 6 months of starting (the median), counting those still running; a quarter within 3 and three quarters within 15. This study's 2 months is below that.
Counting every sponsor, half of 3,943 studies reached it within 12 months; a quarter within 5 and three quarters within 28.
Completion moved once since we started tracking on Sep 25, 2026: Aug 2026 → Oct 2026, on Sep 25, 2026.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Nordic Biotic Sp. z o.o.