Evaluating the Ability of a Multi-Strain Postbiotic to Impact Inflammation, Immune Components, Gastrointestinal Symptoms, Recovery, Anxiety, and Intestinal Permeability

This study is designed to evaluate the effects of a multi-strain postbiotic supplement on physiological, gastrointestinal, and psychological responses to a standardized bout of aerobic exercise in healthy adults. Prolonged moderate-to-high intensity exercise is known to acutely increase inflammatory activity, alter immune function, disrupt gastrointestinal integrity, and influence perceptions of recovery and anxiety. Nutritional interventions that can modulate these responses may be beneficial for supporting health and resilience in physically active populations. Postbiotics, which consist of non-viable microbial cells and their metabolic byproducts, have been proposed to influence immune and gastrointestinal function while avoiding some of the stability and safety concerns associated with live probiotics.

Approximately 50 healthy men and women aged 18 to 55 years will be recruited to participate in a randomized, double-blind, placebo-controlled, parallel-group clinical trial. Eligible participants will be randomly assigned to receive either a multi-strain postbiotic supplement or a matched placebo for 28 consecutive days. Both participants and investigators will remain blinded to treatment assignment for the duration of the study.

Participants will be instructed to maintain their habitual diet, physical activity, and lifestyle behaviors throughout the supplementation period and to avoid the use of additional probiotic, prebiotic, or immune-modulating supplements. Compliance with supplementation will be monitored by self-report and capsule counts.

At the end of the 28-day supplementation period, participants will complete a standardized 45-minute treadmill exercise bout performed at 75% of their individually determined maximum heart rate. This exercise protocol is designed to induce a controlled physiological stress that elicits measurable inflammatory, immune, and gastrointestinal responses.

Blood samples will be collected to assess biomarkers related to inflammation, immune function, and recovery. Gastrointestinal symptoms, intestinal permeability, anxiety, and perceived recovery will be assessed using validated questionnaires administered before and after the exercise challenge.

Safety will be monitored throughout the study through the collection of self-reported adverse events and investigator assessment.

This study will determine whether supplementation with a multi-strain postbiotic alters physiological and perceptual responses to prolonged aerobic exercise compared with placebo in healthy adults.

Inclusion criteria

Healthy males and females aged 18 to 55 years of age. Individual indicates they are physically active defined as: 30 minutes of moderate intensity activity 4 days per week in the past 3 months.

Subject has the ability to exercise on a treadmill without issue or concern. Body Mass Index (BMI) 18.0-32.0 kg/m2 (normal weight to obesity weight). The average BMI of the entire cohort will be <30.0 kg/m2.

Subject is in good health and appropriate for exercise as determined by physical examination and medical history.

Subject can exercise on a treadmill without issue or concern. Subject is a non-smoker. Subject agrees to not use any new vitamin, mineral, or dietary supplements 24 hours prior to the exercise test visits.

Subject is willing and able to comply with the protocol including: attending the study scheduled appointments, of which two of the study visits may take up to four hours of completion.

Subject agrees to refrain from exercise for the 24 hours prior to any test visits.

Subject agrees to refrain from alcohol use for at least 24 hours before every study visit.

Subject is able to understand and sign the informed consent to participate in the study.

Exclusion criteria

Individuals who are determined to have liver, renal, cardiovascular, or other metabolic disease.

Use of any dietary supplements, prescription mediation (particularly antibiotics and/or anti-inflammatories), or probiotics within the past 2 months which may confound the study or its endpoints.

Alcohol consumption (>2 standard alcoholic drinks/day or >10 drinks/week) or drug abuse/dependence.

Smokers (defined as greater than 2 cigarettes per day for past 90 days). Clinically significant abnormal laboratory results at screening. Allergy or sensitivity to study supplement ingredients. Individuals who are cognitively impaired and/or who are unable to give informed consent.

Individuals with diabetes, asthma, rheumatoid arthritis, colitis, IBS/IBD, gout, or fibromyalgia.

Any other condition which in the PI's opinion may adversely affect the subject's ability to complete the study, its measurement or poses significant risk to the subject.