Obesity and its associated disease: a role for microbiota?

Abstract

Background: Gut microbiota have recently been implicated in the pathogenesis of the obesity and its related metabolic diseases. A variety of factors including diet, genetic background, environment and host innate and adaptive immune responses define an individual's gut microbiota.

Purpose: In this review we outline potential mechanisms by which gut microbiota can contribute to the development of obesity focusing on specific processes such as microbial energy extraction, microbiota induced-inflammation and regulation of appetite. We review the current understanding of each of these processes on regulating metabolism and examine potential therapeutic strategies for the treatment or prevention of the metabolic syndrome. We explore the hypothesis that alteration in gut microbiota may be an initial event leading to altered feeding behavior and/or systemic inflammation, ultimately leading to weight gain and the metabolic syndrome.

Figure 1

Schematic diagram of proposed mechanism of gut microbiota regulation of obesity. A variety of factors shape the human gut microbiota. The microbiota in turn can influence metabolic pathways by modulating energy extraction, inflammation and satiety, leading to the development of obesity. Abbreviations: SCFA: Short chain fatty acids; SREBP-1: Sterol Regulatory Element Binding protein-1; ChREBP:Carbohydrate Response Element Binding Protein; NPY: Neuropeptide Y; PYY: Peptide YY; GLP-1: Glucagon Like peptide-1; TLR4: Toll-like receptor 4, T5KO: TLR5 Knock out; LPS: Lipopolysaccharide