Background Gut microbiota have recently been implicated in the pathogenesis of the obesity and its related metabolic diseases. A variety of factors including diet, genetic background, environment and host innate and adaptive immune responses define an individual’s gut microbiota.
Purpose In this review we outline potential mechanisms by which gut microbiota can contribute to the development of obesity focusing on specific processes such as microbial energy extraction, microbiota induced-inflammation and regulation of appetite. We review the current understanding of each of these processes on regulating metabolism and examine potential therapeutic strategies for the treatment or prevention of the metabolic syndrome. We explore the hypothesis that alteration in gut microbiota may be an initial event leading to altered feeding behavior and/or systemic inflammation, ultimately leading to weight gain and the metabolic syndrome.