title: Potential mediators linking gut bacteria to metabolic health: a critical view.
abstract: Growing evidence suggests that the bacteria present in our gut may play a role in mediating the effect of genetics and lifestyle on obesity and metabolic diseases. Most of the current literature on gut bacteria consists of cross-sectional and correlative studies, rendering it difficult to make any causal inferences as to the influence of gut bacteria on obesity and related metabolic disorders. Interventions with germ-free animals, treatment with antibiotic agents, and microbial transfer experiments have provided some evidence that disturbances in gut bacteria may causally contribute to obesity-related insulin resistance and adipose tissue inflammation. Several potential mediators have been hypothesized to link the activity and composition of gut bacteria to insulin resistance and adipose tissue function, including lipopolysaccharide, angiopoietin-like protein 4, bile acids and short-chain fatty acids. In this review we critically evaluate the current evidence related to the direct role of gut bacteria in obesity-related metabolic perturbations, with a focus on insulin resistance and adipose tissue inflammation. It is concluded that the knowledge base in support of a role for the gut microbiota in metabolic regulation and in particular insulin resistance and adipose tissue inflammation needs to be strengthened.
authors.affiliation: Nutrition, Metabolism and Genomics Group, Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands.
authors.forename: Aafke W F
authors.initials: AW
authors.lastname: Janssen
authors.affiliation: Nutrition, Metabolism and Genomics Group, Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands.
authors.forename: Sander
authors.initials: S
authors.lastname: Kersten
mesh_terms: D000075803:Angiopoietin-Like Protein 4; D042682:Angiopoietins / Q000378:metabolism*; D000818:Animals; D001647:Bile Acids and Salts / Q000378:metabolism*; D005232:Fatty Acids, Volatile / Q000378:metabolism*; D000069196:Gastrointestinal Microbiome; D041981:Gastrointestinal Tract / Q000378:metabolism / Q000382:microbiology; D006801:Humans; D008070:Lipopolysaccharides / Q000378:metabolism*; D008659:Metabolic Diseases / Q000378:metabolism / Q000382:microbiology
chemical_list: C474772:ANGPTL4 protein, human; D000075803:Angiopoietin-Like Protein 4; D042682:Angiopoietins; D001647:Bile Acids and Salts; D005232:Fatty Acids, Volatile; D008070:Lipopolysaccharides
keywords: adipose tissue inflammation; angiopoietin-like protein 4; bile acids; gut bacteria; insulin resistance; lipopolysaccharide; short-chain fatty acids