An interventional study of Probiotic capsules and Placebo in Gut Microbiome, Immune Responses and Well-being, sponsored by Orthomol Pharmazeutische Vertiebs GmbH. Recruiting at 1 site in Germany. Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-08-21.
Sponsored by Orthomol Pharmazeutische Vertiebs GmbH · Not applicable, Interventional, and Prevention
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This randomized, double-blind, placebo-controlled exploratory study will evaluate the effects of daily probiotic supplementation on gut barrier function, immune-related markers, and well-being in healthy adults with mild to moderate perceived stress.
50 participants will be randomly assigned to receive either a probiotic supplement or placebo for 8 weeks. Blood and stool samples will be collected before and after the intervention to assess markers of gut barrier function, intestinal inflammation, gut microbiome composition, short-chain fatty acids, and immune function. Participants will also complete questionnaires on stress, quality of life, mood, digestive symptoms, and bowel habits. Safety will be evaluated throughout the study by monitoring adverse events and vital sign assessments.
This is a prospective, randomized, double-blind, placebo-controlled, singlecenter, two-arm, parallel-group exploratory study in 50 healthy adults with mild to moderate levels of perceived stress.
The study lasts a total of 9 weeks per participant with a 1-week run-in period followed by 8 weeks of supplementation. The study includes three visits to the study site: a screening visit, a pre-intervention visit (at the end of the run-in period), and a post-intervention visit after 8 weeks of supplementation. After providing written informed consent, participants will undergo screening to confirm eligibility. Screening assessments include demographic information, medical history, concomitant medication, body weight, height, body mass index, blood pressure, pulse, and assessment of chronic stress. A pregnancy test will be performed for female participants, as applicable.
Participants are randomly assigned to receive either the probiotic supplement or a matching placebo. Randomization will be stratified by sex. Participants will take one capsule once daily before or with dinner for 56 days.
The probiotic product contains fructooligosaccharides, selected probiotic bacterial strains, and vitamins. The placebo does not contain those active ingredients and is similar in appearance, taste and smell. Treatment allocation will remain blinded to participants and the study team involved in study assessments. Blood and stool samples will be collected before and after the intervention. Laboratory assessments will include markers related to gut barrier function, intestinal inflammation, gut microbiome composition, short-chain fatty acids, and systemic immune function. Further, participants will complete questionnaires assessing quality of life, health-related quality of life, depression, anxiety, stress, bloating, flatulence, stool consistency, and stool frequency. Safety will be evaluated by monitoring adverse events, blood pressure, and pulse. During the complete study duration, participants are instructed to maintain their usual lifestyle and diet.
This is the only study on the registry with Orthomol Pharmazeutische Vertiebs GmbH as lead sponsor.
Counted across the registry records on this site, refreshed daily.
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.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
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 reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Fructooligosaccharides, selected probiotic strains, vitamins
Dietary Supplement: Probiotic capsules
Maltodextrin, corn starch
Other: Placebo
Fructooligosaccharides, selected probiotic strains, vitamins
Maltodextrin, corn starch
Gut barrier function
Gut barrier function
Time frame: During 8 week intake phase
Immune function
Immune function
Time frame: During 8 week intake phase
Well-being
Perceived (health-related) quality of life, stress, anxiety, depression
Time frame: During 8 weeks intervention phase
Started Aug 2026 (actual). Primary completion is estimated for Dec 2026, 4 months after the start.
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Studies of the drug tested here: Probiotic