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

Overview

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.