title: The Gut Microbiota Modulates Energy Metabolism in the Hibernating Brown Bear Ursus arctos.
abstract: Hibernation is an adaptation that helps many animals to conserve energy during food shortage in winter. Brown bears double their fat depots during summer and use these stored lipids during hibernation. Although bears seasonally become obese, they remain metabolically healthy. We analyzed the microbiota of free-ranging brown bears during their active phase and hibernation. Compared to the active phase, hibernation microbiota had reduced diversity, reduced levels of Firmicutes and Actinobacteria, and increased levels of Bacteroidetes. Several metabolites involved in lipid metabolism, including triglycerides, cholesterol, and bile acids, were also affected by hibernation. Transplantation of the bear microbiota from summer and winter to germ-free mice transferred some of the seasonal metabolic features and demonstrated that the summer microbiota promoted adiposity without impairing glucose tolerance, suggesting that seasonal variation in the microbiota may contribute to host energy metabolism in the hibernating brown bear.
authors: The Wallenberg Laboratory, Department of Molecular and Clinical Medicine, University of Gothenburg, 41345 Gothenburg, Sweden; Institute for Clinical Molecular Biology, University of Kiel, Schittenhelmstraße 12, 24105 Kiel, Germany.
authors: Felix
authors: F
authors: Sommer
authors: The Wallenberg Laboratory, Department of Molecular and Clinical Medicine, University of Gothenburg, 41345 Gothenburg, Sweden.
authors: Marcus
authors: M
authors: Ståhlman
authors: Sarah W. Stedman Nutrition and Metabolism Center and Duke Molecular Physiology Institute and Departments of Pharmacology and Cancer Biology and Medicine, Duke University Medical Center, Durham, NC 27701, USA.
authors: Olga
authors: O
authors: Ilkayeva
authors: Faculty of Forestry and Wildlife Management, Hedmark University College, 2418 Elverum, Norway; Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden.
authors: Jon M
authors: JM
authors: Arnemo
authors: Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden.
authors: Jonas
authors: J
authors: Kindberg
authors: Department of Cardiology, Faculty of Health, Örebro University, 70185 Örebro, Sweden.
authors: Johan
authors: J
authors: Josefsson
authors: Sarah W. Stedman Nutrition and Metabolism Center and Duke Molecular Physiology Institute and Departments of Pharmacology and Cancer Biology and Medicine, Duke University Medical Center, Durham, NC 27701, USA.
authors: Christopher B
authors: CB
authors: Newgard
authors: Department of Cardiology, Faculty of Health, Örebro University, 70185 Örebro, Sweden.
authors: Ole
authors: O
authors: Fröbert
authors: The Wallenberg Laboratory, Department of Molecular and Clinical Medicine, University of Gothenburg, 41345 Gothenburg, Sweden; Novo Nordisk Foundation Center for Basic Metabolic Research, Section for Metabolic Receptology and Enteroendocrinology, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark. Electronic address: fredrik.backhed@wlab.gu.se.
authors: Fredrik
authors: F
authors: Bäckhed
mesh_terms: D039903:Actinobacteria / Q000145:classification / Q000254:growth & development; D000222:Adaptation, Physiological; D050154:Adiposity / Q000502:physiology*; D000818:Animals; D041963:Bacteroidetes / Q000145:classification / Q000254:growth & development; D001647:Bile Acids and Salts / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D002331:Carnitine / Q000031:analogs & derivatives / Q000097:blood; D002784:Cholesterol / Q000097:blood; D004734:Energy Metabolism / Q000502:physiology*; D000069467:Fecal Microbiota Transplantation; D005243:Feces / Q000382:microbiology; D000068536:Bacillota / Q000145:classification / Q000254:growth & development; D000069196:Gastrointestinal Microbiome / Q000502:physiology*; D005856:Germ-Free Life; D006605:Hibernation / Q000502:physiology*; D051379:Mice; D025341:Principal Component Analysis; D012621:Seasons; D014280:Triglycerides / Q000097:blood; D001503:Ursidae / Q000097:blood / Q000382:microbiology*
chemical_list: D001647:Bile Acids and Salts; D001786:Blood Glucose; D014280:Triglycerides; C116917:acylcarnitine; D002784:Cholesterol; D002331:Carnitine
keywords: brown bear; hibernation; metabolism; microbiota; obesity