The potential role of the gut microbiota in various human diseases has attracted considerable attention worldwide. Here, we discuss the vital role of the intestinal microbiota in the development of obesity. First, we describe how the gut microbiota promotes fat accumulation. Additionally, a high-fat diet leads to structural instability among in the gut microbiota, further leading to an increase in endotoxins, which aggravates obesity. We then discuss how gut microbiota metabolites, including short-chain fatty acids and lipopolysaccharides, affect the host. Finally, we review several strategies for regulating the intestinal flora. [ABSTRACT FROM AUTHOR]