Chapter 12 - Influence of Dietary Factors on Gut Microbiota: The Role on Insulin Resistance and Diabetes Mellitus

Abstract

Human gut microbiota consists of trillions of microorganisms and thousands of bacterial phylotypes that are deeply involved in a different function of host metabolism. The collective genomes of our gut microbes (microbiome) may contain >150 times more genes than our own genome. Eighty to ninety percent of the bacterial phylotypes are members of two phyla: the Bacteroidetes (Gram-negative) and the Firmicutes (Gram-positive), followed by Actinobacteria (Gram-positive) and Proteobacteria. Recent studies have described dietary intervention impact on gut microbial gene richness. Initial studies on gut microbial composition and function were limited by the difficulty to culture all intestinal microbes. The introduction of bacterial genome sequencing and “metagenomic” analysis has contributed to increased knowledge about uncultivable microbes, gut microbial functions, its cross-talk with the host, and the potential pathogenic role related to host's diseases.