ABSTRACT
Our intestinal tract is colonized since birth by complex communities of microbes that show specific spatiotemporal organizations, differ in composition between individuals, and contribute to health and disease (Zoetendal et al., 2006). Considerable progress has been made in recent years to describe the structure and function of the intestinal microbiota that belong to the major phyla of the Firmicutes, Actinobacteria, Bacteroidetes, Proteobacteria and Verrucomicrobia (Rajilić-Stojanović et al., 2007). However, the majority of the over 1000 species-like groups of the human intestine have not yet been cultured (Zoetendal et al., 2008). Facilitated by the advances in sequencing technologies, significant attention has been given to culture-independent and high-throughput approaches that generated important baseline information on the intestinal microbiota composition, the description of a reference metagenome of 3.3 Mb, and its structuring into
clusters, termed enterotypes (Qin and the MetaHit Consortium, 2010; Arumugam and the MetaHit Consortium, 2011; Huttenhower and the Human Microbiome Project Consortium, 2012).
