Digestion and Absorption of Postbiotic Regulatory Proteins

The goal of this clinical trial is to find out whether a daily postbiotic supplement can help healthy, physically active adults digest and absorb dietary protein better. The main question we aim to answer is: does taking a postbiotic for 12 weeks increase the levels of essential amino acids in the blood after eating a protein-rich meal? Participants will be randomly assigned to one of two groups. One group will receive the postbiotic supplement, and the other group will receive a placebo (a substance with no active therapeutic effect). Everyone will take their assigned supplement once daily for 12 weeks. During the study, participants will have regular health checks, including body composition and muscle strength tests, provide stool samples, and complete a protein tolerance test with blood samples taken before and after the meal. This study is important because it explores whether a postbiotic can help active adults get more benefit from the protein they eat, potentially offering a new way to support muscle and digestive health.

Inclusion Criteria: 1. Age: 18-45 years; open to all genders; 2. Body weight has remained stable over the preceding 3 months (change \< 5%); 3. Willing to maintain their previous dietary and exercise habits with minimal change during the study period; 4. Have maintained regular training over the past 3 months, with an average of ≥ 3 sessions/week and each session lasting ≥ 30 minutes; 5. Voluntarily participate and sign a written informed consent form, and be able to complete follow-up visits, blood sampling, stool sampling, and questionnaire completion as required. Exclusion Criteria: 1. History of or current presence of severe gastrointestinal disorders (e.g., inflammatory bowel disease, significant malabsorption following gastrointestinal surgery), or other conditions that the investigator deems likely to affect nutrient absorption or the assessment of intestinal parameters; 2. Use of antibiotics or probiotics within the past 4 weeks; 3. Use of any protein powder, BCAA, creatine, HMB, etc., within the past 4 weeks; 4. Use of medications that affect protein metabolism (e.g., glucocorticoids, androgenic drugs) within the past 4 weeks; 5. Presence of severe cardiovascular, hepatic, renal, or metabolic disorders (e.g., uncontrolled hypertension, diabetes mellitus), or conditions that contraindicate participation in the physical performance test; 6. History of severe musculoskeletal injury or recent surgery within the past 3 months; 7. Pregnancy or lactation status; 8. Other conditions under which the investigator deems participation in this study unsuitable, or where adherence to study protocols is unlikely.