The gut microbiota, particularly *Akkermansia muciniphila*, is recognized as a key factor in regulating host health. This review explores the potential of *A. muciniphila* in ameliorating metabolic diseases, including obesity, type 2 diabetes (T2DM), cardiovascular disease (CVD), and nonalcoholic fatty liver disease (NAFLD). *A. muciniphila* is an anaerobic, Gram-negative bacterium that colonizes the gastrointestinal tract, primarily in the mucus layer, and is highly abundant in humans and animals. Its abundance is influenced by factors such as age, diet, disease, and antibiotics. Studies have shown that *A. muciniphila* abundance is reduced in individuals with metabolic diseases, suggesting a direct or indirect association. Supplementation with *A. muciniphila* has been found to alleviate obesity, T2DM, CVD, and NAFLD by improving intestinal barrier function, reducing insulin resistance, and modulating lipid metabolism. The review highlights the mechanisms by which *A. muciniphila* exerts these effects, including the production of short-chain fatty acids, the regulation of gene expression, and the enhancement of immune responses. Despite its promising potential, further research is needed to fully understand the molecular mechanisms and to develop clinical applications.The gut microbiota, particularly *Akkermansia muciniphila*, is recognized as a key factor in regulating host health. This review explores the potential of *A. muciniphila* in ameliorating metabolic diseases, including obesity, type 2 diabetes (T2DM), cardiovascular disease (CVD), and nonalcoholic fatty liver disease (NAFLD). *A. muciniphila* is an anaerobic, Gram-negative bacterium that colonizes the gastrointestinal tract, primarily in the mucus layer, and is highly abundant in humans and animals. Its abundance is influenced by factors such as age, diet, disease, and antibiotics. Studies have shown that *A. muciniphila* abundance is reduced in individuals with metabolic diseases, suggesting a direct or indirect association. Supplementation with *A. muciniphila* has been found to alleviate obesity, T2DM, CVD, and NAFLD by improving intestinal barrier function, reducing insulin resistance, and modulating lipid metabolism. The review highlights the mechanisms by which *A. muciniphila* exerts these effects, including the production of short-chain fatty acids, the regulation of gene expression, and the enhancement of immune responses. Despite its promising potential, further research is needed to fully understand the molecular mechanisms and to develop clinical applications.