Download or read book Dietary and Pharmacologic Regulation of the Gut Microbiome: Implications for Health and Disease written by Edmond Yii-Ming Huang and published by . This book was released on 2013 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over 100 trillion bacteria live in our gastrointestinal tract, comprising an ecosystem that exceeds the number of our cells by over ten-fold and is far more genetically diverse. Countless years of evolutionary pressures have driven these resident microbes, termed gut microbiota, to genetically and functionally evolve in ways that foster a mutualistic relationship with their hosts. For example, gut microbiota are known to subsist on indigestible carbohydrates, metabolizing them into readily-available short-chain fatty acids (SCFAs) beneficial to their host. Over the past decade, a rapid emergence of culture-independent, high-throughput in silico 16S ribosomal RNA sequencing technologies have provided scientists the necessary tools to more deeply and efficiently characterize the gut microbiota. Researchers have uncovered a multitude of critical metabolic, immune, and developmental pathways that are critically affected by gut microbes, which, when awry, have led to diseases that include colon cancer, metabolic syndrome, obesity, asthma, inflammatory bowel diseases, and olther complex immune disorders. We hypothesize that both dietary as well as pharmacologic factors are capable of altering the composition and function of gut microbial communities to mediate effects that contribute physiologically as well as pathophysiologically. In the first study, we demonstrate that the consumption of specific dietary fats alters gut microbiota, which then promotes the expression of inflammatory genes in adipose tissue. This action may be a key step towards setting up the conditional requirements that eventually lead to metabolic disturbances, Type 2 diabetes, and obesity. Our second study explores the pharmacologic mechanisms of action of glucocorticoids which are widely used clinically, albeit their actions are still incompletely understood. We report that chronic exposure to the synthetic glucocorticoid dexamethasone (DEX) reshapes the gut microbiota in a way that affects colonic mucin expression. Our findings suggest that these actions may in part contribute to the anti-inflammatory effects observed in a genetically susceptible mouse model of colitis. Altogether, the studies highlight how susceptible host-microbe interactions can be to dietary and pharmacological influences. These effects can promote host health on the one hand, but, on the other, contribute to the development of disease. We believe this knowledge can be used to our advantage in developing novel diagnostic and therapeutic strategies and for lowering risk of disease.