Effects of gut microbiota on obesity and atherosclerosis via modulation of inflammation and lipid metabolism.

Recent studies have revealed a close relationship between inflammatory and metabolic pathways, and inflammation is now recognized to have a major role in obesity and metabolic diseases such as insulin resistance and atherosclerosis. The human body is home to a large number of distinct microbial communities, with the densest population in the distal gut (the gut microbiota). Bacteria have long been known to activate inflammatory pathways, and recent data demonstrate that the gut microbiota may affect lipid metabolism and function as an environmental factor that influences the development of obesity and related diseases. Here, we review how the gut microbiota may affect metabolic diseases by activating the innate immune system.