Author Interviews, Brigham & Women's - Harvard, Genetic Research, Microbiome / 24.07.2018
Changing One Gene in One Gut Bacteria Altered Metabolism and Weight Gain (in mice)
MedicalResearch.com Interview with:
A. Sloan Devlin, PhD
Assistant Professor
Department of Biological Chemistry and Molecular Pharmacology
Harvard Medical School
MedicalResearch.com: What is the background for this study?
Response: It is known that the microbiome, the collection of bacteria that live in and on our bodies, influences the development of metabolic diseases including diabetes and obesity. The ways in which the microbiome affects host metabolism, however, are poorly understood. One reason for this lack of understanding is because the gastrointestinal tract contains hundreds of species of bacteria producing many different kinds of metabolites. Untangling the effects of these bacteria and the molecules they make is a significant challenge.
In this study, we decided to concentrate on a group of metabolites found in the human gut called bile acids. When we eat a meal, these compounds are released into the gastrointestinal tract where they act as detergents that aid in digestion. Once these molecules reach the lower gastrointestinal tract, the gut bacteria residing there chemically modify these compounds, producing a pool of over 50 different bile acids total.
Imbalances in this bile acid pool are thought to influence the progression of diet-induced obesity. However, it is unclear which specific bile acids are responsible for either beneficial or detrimental effects on host metabolism. We set out to address this question by first identifying a selective type of bacterial enzyme called a bile salt hydrolase, then by genetically deleting this enzyme from a common gut bacterium and investigating how this change affected host metabolism.
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