As a next-generation probiotic, the therapeutic advantages of Akkermansia muciniphila (A. muciniphila) in metabolic diseases have been widely demonstrated. However, the exclusion of A. muciniphila from the List of Approved Food Microbial Strains in China creates regulatory barriers for conducting clinical trials, leading to a significant lack of clinical evidence. In this study, 130 overweight participants were randomly assigned to receive a placebo (PLA), viable A. muciniphila PROBIO (PB), or A. muciniphila PROBIO postbiotics (POST) intervention for 8 weeks. Our results demonstrated that, after 8 weeks of intervention, both the PB group (PB vs PLA = -0.63 vs 1.272, P < 0.001) and the POST group (POST vs PLA = -0.63 vs 0.43, P < 0.001) demonstrated significantly greater weight reduction compared to the PLA group. Additionally, the viable A. muciniphila PROBIO and postbiotics interventions significantly improved liver function, lipid metabolism, emotional well-being, and gut microbiota composition. Notably, the viable A. muciniphila intervention significantly enhanced key metabolic parameters, including total bilirubin (p = 0.031), triglycerides (P < 0.001), total cholesterol (p = 0.023), and LDL-C (p = 0.044), demonstrating an overall efficacy that exceeds its postbiotics, which contradicts current mainstream views. In conclusion, this study systematically evaluated the effects of viable A. muciniphila PROBIO and its postbiotics in overweight individuals, confirming their ability to improve overweight-related metabolic disorders through various mechanisms, including reducing lipid accumulation, modulating liver function, and reshaping gut microbiota. These findings provide a theoretical foundation and data support for developing products and clinical applications of A. muciniphila PROBIO in managing metabolic disorders such as overweight and obesity.