[Impact of newly developed metagenomic tools on our knowledge of the gut microbiota and its role in human health: diagnostic and therapeutic issues].

Over the last years, our vision of the intestinal microbiota and its contribution to human physiology has been fully revisited, thanks to metagenomics. Next generation sequencing allowed a full characterization of the microbiome. Quantitative metagenomic permitted a deep understanding of the intestinal ecosystem, its structure, and potential dysbiosis in several human pathologies. The microbiome may be used as biomarker of disease or of risk to progress toward a disease. A good understanding of the mechanisms of interaction between gut microbiota and its host is needed; functional metagenomic is a useful tool to identify genes and metabolites able to interact with host's cells. Overall, the microbiome science that is developing opens new avenue for diagnosis, discovery of new drugs and potential therapeutic approaches. It is also a target for modulation by food, with potential impact on health.