The ‘Gut Microbiota for Health’ world congress has closed its 2nd edition after three days of intense discussions about the latest researches in the field of gut microbiota. Nearly 300 professionals have attended the lectures and the multidisciplinary workshops, focused on the microbiota as an organ with its own roles and relations with other systems of the organism. It is the case of the relation of the microbiota with the behavior that has presented Dr. Emerand Mayer, from the David Geffen School of Medicine (USA). In a study with 45 women using magnetic resonance imaging, she has detected subtle changes in the brain which show that bacterial colonization has influence in the behavior after the ingestion of probiotics. Besides this study, the relation of microbiota with obesity has also been tackled. Professor Patrice D. Cani, from the University of Louvain (Belgium), has demonstrated how prebiotics are useful to strength the gut barrier that in obese patients is leaky, so toxic molecules can permeate this wall.During the summit, researchers and professionals have also reviewed the conclusions of the European project MetaHIT, coordinated at VHIR, and the Human Microbiome Project, which is giving outstanding information about the composition of gut microbiota.For Dr. Fernando Azpiroz, head of the Group of Phisiology and Pathophisiology of the Digestive Tract at VHIR and chairman of ESNM’s Gut Microbiota & Health Section, the summit has been a success: “It has been a great opportunity to join in a same place professionals from all over the world with a long experience and interest in the field of microbiota and its effects in different areas. In many occasions, it was difficult to distinguish the speaker in the workshops because there was a lot of interaction with participants.Dr. Francisco Guarner, member of the same group at VHIR, has led the scientific committee of this congress organized by the European Society of Neurogastroenterology and Motility, together with the American Gastroenterological Association, the 24th, 25th and 26th of February in Madrid.