Can Gut Bacteria Predict Who Benefits Most From Exercise? A Gut Supplement to Help Exercise Non-Responders

This is a single-arm, interventional study investigating the role of the gut microbiome in mediating the effects of cardiovascular exercise on insulin sensitivity in adult females with overweight or obesity (BMI ≥25). The study also evaluates the effectiveness of sodium butyrate supplementation in enhancing insulin sensitivity among individuals who are otherwise non-responsive to exercise alone. The study will enroll 40 female participants between the ages of 18 and 40, who have been sedentary for at least six months. Exclusion criteria include a diagnosis of diabetes or hypertension, recent weight changes, use of antibiotics, probiotics, or weight loss supplements, and any condition contraindicating safe participation in exercise. Participants will engage in a 12-week supervised cardiovascular exercise program at the TCU Recreation Center. Exercise will progress from 30 to 60 minutes per session, 5 days per week, with intensity increasing from 50% to 80% of estimated maximum heart rate. During weeks 8 through 12, participants will take sodium butyrate (BodyBio; 939 mg sodium/day) in capsule form, dosed at 2 capsules with each meal (6 total/day). Data collection includes: * Stool samples (3 total): collected pre-intervention, at week 8 (pre-supplementation), and at week 12 (post-supplementation), to evaluate changes in gut microbial composition and diversity. * Blood samples (3 total): fasting blood draws at the same three time points to measure glucose and insulin for calculation of HOMA-IR and other insulin sensitivity indices. * Body composition: assessed at three time points using Dual-Energy X-ray Absorptiometry (DEXA) to determine fat mass, lean mass, and bone mineral density. * Questionnaires: validated instruments assessing physical activity, dietary intake, sleep, anxiety, depression, and food cravings. * Blood pressure: at the beginning of the study, and every week during the supplementation phase The primary outcomes include changes in insulin sensitivity and gut microbiota composition across the 12-week intervention. Secondary outcomes include body composition changes and the classification of participants as "responders" or "non-responders" to exercise based on insulin sensitivity improvements. An exploratory objective is to develop predictive models using AI algorithms (e.g., decision trees, random forests, support vector machines, logistic regression) trained on baseline gut microbiota and blood biomarkers to predict individual response to exercise. This study is internally funded by a TCU Innovation Scholars (IS) Grant (\~$20,000), with an in-kind supplement donation valued at $2,000 provided by BodyBio. The study is conducted entirely on the TCU campus and has been approved by the TCU Institutional Review Board (IRB #2025-217). Results from this study aim to advance personalized exercise strategies and contribute to the growing field of precision medicine.