Obese Microbiota Research Articles

Microecology, obesity, and probiotics

Description of the role that the microbiota may play in human health, energy harvest, and obesity. The adult human gut may contain up to 100 trillion microbial organisms, known as the microbiota. Major advances in defining the quality, quantity, and physiologic activity of the intestinal microbiota were precipitated by the conversion from culture-based techniques to metagenomics. The microbiota may serve various functions including promoting development of the human immune system, modulating inflammation, and affecting calorie extraction. Recent evidence, in humans and animal models, supports a role for the microbiota in obesity. Not only is the presence of bacteria important, but also the relative proportions of microbial communities, specifically Firmicutes and Bacteriodetes, appear to be important in energy homeostasis. The microbiota may also affect the immune and inflammatory response in human organisms. Although there is limited data supporting the manipulation of the gut microbiota, using probiotics, antibiotics, and/or prebiotics to treat obesity, novel therapeutic agents may be developed.

An obesity-associated gut microbiome with increased capacity for energy harvest

The worldwide obesity epidemic is stimulating efforts to identify host and environmental factors that affect energy balance. Comparisons of the distal gut microbiota of genetically obese mice and their lean littermates, as well as those of obese and lean human volunteers have revealed that obesity is associated with changes in the relative abundance of the two dominant bacterial divisions, the Bacteroidetes and the Firmicutes. Here we demonstrate through metagenomic and biochemical analyses that these changes affect the metabolic potential of the mouse gut microbiota. Our results indicate that the obese microbiome has an increased capacity to harvest energy from the diet. Furthermore, this trait is transmissible: colonization of germ-free mice with an 'obese microbiota' results in a significantly greater increase in total body fat than colonization with a 'lean microbiota'. These results identify the gut microbiota as an additional contributing factor to the pathophysiology of obesity.