Metabolic diseases such as obesity and diabetes have been the most serious social and health problems in the world. Current treatments mainly focus on the disease consequence rather than the cause of metabolic disorders, and it is difficult to curb the global trend of explosive growth of patients. Thus new and more effective prevention and treatment strategies are needed. Genetics and environment influence the process of obesity and diabetes. But the genomic analysis only ac counts for 10% to 20% of the metabolic diseases, while environmental factors such as diet and other lifestyle habits play an important role in the onset of metabolic diseases. In recent years, an increasing number of studies have shown that human gut microbiota is closely related to the onset and development of metabolic diseases such as obesity and type 2 diabetes. The rapid progress in this emerging academic field will not only help elucidate the pathogenesis of metabolic disease, but will also provide direction for exploring new thera