The Human Intestinal Microbiome: A New Frontier of Human Biology

To analyze the vast number and variety of microorganisms inhabitingthe human intestine, emerging metagenomic technologies are extremelypowerful. The intestinal microbes are taxonomically complexand constitute an ecologically dynamic community (microbiota)that has long been believed to possess a strong impact on humanphysiology. Furthermore, they are heavily involved in the maturationand proliferation of human intestinal cells, helping to maintaintheir homeostasis and can be causative of various diseases,such as inflammatory bowel disease and obesity. A simplifiedanimal model system has provided the mechanistic basis for themolecular interactions that occur at the interface between suchmicrobes and host intestinal epithelia. Through metagenomicanalysis, it is now possible to comprehensively explore thegenetic nature of the intestinal microbiome, the mutually interactingsystem comprising the host cells and the residing microbialcommunity. The human microbiome project was recently launchedas an international collaborative research effort to furtherpromote this newly developing field and to pave the way to anew frontier of human biology, which will provide new strategiesfor the maintenance of human health.