• Intestinal bacteria
• intestinal microbiology
• molecular mechanisms
• nuclear magnetic resonance
• obesity

Obesity and type 2 diabetes are becoming worldwide epidemics. In this regard, the literature provides evidence that low-grade inflammation contributes to the onset of the metabolic disorders associated with overweight and obesity (insulin resistance, type 2 diabetes, cardiovascular diseases).1 A considerable number of factors have been associated with the development of obesity, including the gut microbiota. The novel concept, that we defined as ‘MicrObesity’ (Microbes and Obesity), is devoted to delineating the impact of dysbiosis (changes in gut microbiota composition and/or activity) and its implications on host metabolism and energy storage.2 Although the exact composition of the gut microbiota is not known, advances in metagenomic and metabonomic technologies have recently begun to unravel our microbial partners including the symbiotic complexity of the host–gut microbiota interactions, reflected by a specific chemical signature in the different biofluids.3

Over the last years, bariatric surgical approaches (eg, Roux-en-Y gastric bypass (RYGB) surgery) have provided interesting results, not only in achieving and maintaining appropriate weight loss, but most importantly by the resolution of type 2 diabetes independently of weight changes.4 Although the …