Coevolution of the Human Host and Gut Microbiome: Metagenomics of Microbiota.

It is estimated that humans have trillions of microbial cells living in their gut as part of their microbiota. Each human being has an entirely unique microbiome and human gut microbiota composition has been shown to alter with age due to several factors including physical stress, diet, use of antibiotics, prolonged treatments, chronic disease processes, physiological changes, and geographical location. The gut microbiome contributes to overall well-being in a multitude of ways, including digestion, metabolism, immunity, and the creation of vital compounds that the body cannot synthesize on its own. Disequilibrium in the microbiota has been correlated to obesity, heart disease, irritable bowel disease, and certain cancers. The evolution of the human host allowed for the diversity of the microbial community present in the gut. Although previous studies portray the correlation between diet and disequilibrium in host microbiota, the evolutionary dynamics of bacterial commensal flora and the extent to which it is beneficial are still unclear and need additional investigation.