METABOLISM (P TRAYHURN, SECTION EDITOR) Gut Microbiota Dysbiosis in Obesity-Linked Metabolic Diseases and Prebiotic Potential of Polyphenol-Rich Extracts Fernando F. Anhê 1,2 & Thibault V. Varin 2 & Mélanie Le Barz 1,2 & Yves Desjardins 2 & Emile Levy 2,3,4 & Denis Roy 2 & André Marette 1,2 # Springer Science+Business Media New York 2015 Abstract Trillions of microorganisms inhabit the human body, strongly colonizing the gastro-intestinal tract and outnumbering our own cells. High-throughput sequencing techniques and new bioinformatic tools have enabled scien- tists to extend our knowledge on the relationship between the gut microbiota and host’ s physiology. Disruption of the eco- logical equilibrium in the gut (i.e., dysbiosis) has been asso- ciated with several pathological processes, including obesity and its related comorbidities, with diet being a strong deter- minant of gut microbial balance. In this review, we discuss the potential prebiotic effect of polyphenol-rich foods and extracts and how they can reshape the gut microbiota, emphasizing the novel role of the mucin-degrading bacterium Akkermansia muciniphila in their metabolic benefits. Keywords Prebiotics . Polyphenols . Obesity . Insulin resistance . Akkermansia Introduction The human gastro-intestinal (GI) tract harbors trillions of mi- croorganisms among bacteria, viruses, fungi, and archaea. In the course of evolution, more complex species, like mammals, co-evolved with microorganisms to select for a symbiotic re- lationship that goes beyond aiding the host’ s digestive system, extending to a critical role in physiology. From an evolution- ary perspective, human beings have experienced a sudden shift in lifestyle (e.g., excessive sanitation, industrialized and abundant diet, sedentarism, and antibiotics), which could be harmful for the gut microbiota: an ecosystem carved over millions of years through an evolutionary pressure exerted by environmental and dietary habits very different from the current ones [1–3]. As a consequence, the gut microbiota of the modern man is imbalanced (i.e., dysbiotic), a trait strongly associated with several complex diseases of our times [4–9]. This article is part of the Topical Collection on Metabolism * André Marette andre.marette@criucpq.ulaval.ca Fernando F. Anhê fernando.forato@criucpq.ulaval.ca Thibault V. Varin thibaut.varin.1@ulaval.ca Mélanie Le Barz melanie.lebarz@criucpq.ulaval.ca Yves Desjardins yves.desjardins@fsaa.ulaval.ca Emile Levy emile.levy@recherche-ste-justine.qc.ca Denis Roy denis.roy@inaf.ulaval.ca 1 Department of Medicine, Faculty of Medicine, Cardiology Axis of the Québec Heart and Lung Institute, Laval University, Hôpital Laval, Pavillon Marguerite d’Youville, Québec, QC G1V 4G5, Canada 2 Institute of Nutrition and Functional Foods (INAF), Laval University, 2440 boulevard Hochelaga, Québec, QC G1V 0A6, Canada 3 Research Centre, CHU-Sainte-Justine and Department of Nutrition, Université de Montréal, 3175, Chemin de la Côte Ste Catherine, bureau 5731A, Montreal, QC H3T 1C5, Canada 4 Department of Nutrition, Faculty of Medicine, University of Montreal, Montreal, Québec, Canada Curr Obes Rep DOI 10.1007/s13679-015-0172-9