Probiotic Intervention on Body Weight

The primary goal is to clarify the roles of LC-19 and semaglutide in weight reduction and in improving energy, glucose, and lipid metabolism, while also comparing side effects, adverse events, and long-term outcomes such as weight regain between these two interventions. In addition, the study will explore key factors affecting intervention response to provide evidence for optimizing individualized intervention strategies. In this study, 120 overweight or obese participants (BMI ≥ 24 kg/m²) will be recruited and be randomly assigned to one of the three groups: an energy-restricted nutritional and lifestyle intervention + placebo group (control group), an energy-restricted nutritional and lifestyle intervention plus LC-19 group (probiotic group), or an energy-restricted nutritional and lifestyle intervention plus semaglutide injection group (GLP-1RA group), with a 12-week intervention. In addition, 20 normal-weight participants will be recruited and receive 12-week weight maintenance nutritional and lifestyle interventions. Before and after the 12-week interventions, metabolic homeostasis will be used to characterize metabolic health and to be determined using comprehensive measurements of dynamic changes in postprandial metabolic responses (including energy metabolism, multiple clinical biomarkers, metabolomic signatures, gut microbiota, genetic signatures etc.) after the standardized mixed-meal tolerance test (MMTT; 126.5 g glucose, 30.67 g fat and 34.5 g protein) in whole-room indirect calorimeter under resting conditions. In addition, data from dietary intake, anthropometric measurements, body composition, behavior questionnaires, 14-day continuous glucose monitoring, and 14-day accelerometer-based physical activity and sleep monitoring will also be collected to characterize metabolic homeostasis. During the interventions, participants will receive dietary advice, behavior guidance and nutritional and lifestyle education by dietitian and physicians. App-connected wearable devices will be utilized to monitor their dietary intakes and an app-connected scale will be used to monitor their weight changes during interventions. Additionally, at 6 months post-intervention, a follow-up assessment will be conducted, including questionnaires (consistent with the baseline visit), anthropometry (e.g., height, weight, waist and hip circumference, blood pressure, pulse), clinical laboratory tests (e.g., blood glucose, blood lipids, liver and kidney function), and stool sample collection. The study protocol has been approved by the Ethics Committee of Tongde Hospital of Zhejiang Province.