Abstract: Obesity is an abnormal accumulation of fat caused by metabolic dysfunction, which can lead to various metabolic syndromes such as atherosclerosis, insulin resistance, and dyslipidemia. Obesity threatens modern society's health and economic development and has always been a research focus. Currently, some mechanisms of intestinal flora inhibiting obesity have been reported. However, due to the complexities of intestinal microbial composition, it is unclear which microbial community is directly related to obesity. The structural changes of intestinal flora in obese patients are used as a starting point in this review to elaborate further on the close relationship between the physiological function of intestinal flora and the pathogenesis of obesity. Based on the summary of relevant research progress at home and abroad, it is concluded that probiotics can directly affect the level of inflammatory cytokines and metabolites in the intestine of obese patients, or regulate the balance of intestinal flora to reshape the metabolism of obese hosts. Thus, probiotics and prebiotics would become new avenues for preventing and treating obesity.