Effects of Probiotic Supplementation on Gut Health, Immune Response, and Well-Being

Randomized, Double-Blind, Placebo-Controlled Exploratory Study Assessing the Effects of Probiotic Supplementation on Gut Barrier Function, Immune Response, and Well-Being.

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.

Inclusion Criteria:

• Volunteer is healthy at the time of screening according to participant's own statements.
• TICS SSCS score ≥ 6.
• Male or female aged ≥18 and ≤65 years at the time of screening.
• BMI ≥18.5 and ≤29.9 kg/m².
• Volunteer is able and willing to comply with the study instructions.
• Volunteer is suitable for participation in the study according to the investigator/study personnel.
• Voluntary, written informed consent to participate in the study.

Exclusion Criteria:

• No command of local language.
• Currently diagnosed neurological or psychiatric disorders.
• Gastrointestinal disorders including irritable bowel syndrome (IBS), inflammatory bowel disease (IBD) or other conditions that might affect the gut environment.
• Contraindication or allergy to any ingredient in the verum or Placebo product.
• Use of drugs in the previous 4 weeks before the beginning of intervention.
• Use of laxatives and labelled pre#and probiotics in the previous 2 weeks before the beginning of intervention.
• Participation in another study with any investigational product within 30 days of screening, or less than five elimination half-lives after the last administration of the investigational product (whichever period is longer) or during the study.
• History of drug (recreational) or alcohol abuse.
• Bowel preparation for investigative procedures in the 4 weeks prior to screening.
• Surgical resection of any part of the bowel (excl. appendectomy).
• Pregnant or lactating female, or pregnancy planned during study period, or women of childbearing potential who are not using a medically approved form of contraception (at least three months prior to screening).
• Regular smoking.