The Gut Microbiome in Health and in Disease

Andrew B. Shreiner; John Y. Kao; Vincent B. Young


Curr Opin Gastroenterol. 2015;31(1):69-75. 

In This Article

Accumulation of Data on the Human Microbiome

The tremendous expansion of information collected on the human microbiome in recent years is highlighted by data generated through several large-scale endeavors to characterize the human microbiome, namely the European Metagenomics of the Human Intestinal Tract (MetaHIT) and the National Institutes of Health-funded Human Microbiome Project (HMP).[6,7] In 2010, the initial MetaHIT consortium study[7] reported sequencing 3.3 million nonredundant fecal microbial genes, representing almost 200 times the quantity of microbial DNA sequences reported in all previous studies. In July 2014, a combined set of metagenomic sequencing data from 1267 gut metagenomes from 1070 individuals, including 760 European samples from MetaHIT, 139 American samples from HMP, and 368 Chinese samples from a large diabetes study,[8] was published with a nonredundant gene catalog of 9.8 million microbial genes. Each sample contained about 750 000 genes or about 30 times the number of genes in the human genome, and less than 300 000 genes were shared by greater than 50% of individuals. The majority of the new genes identified in this latest study were relatively rare, found in less than 1% of individuals. This collection is thought to contain nearly a complete set of genes for most human gut bacteria and illustrates the quantity and variability of the human microbiome.