Principal component analysis shows two clusters. Principal component analysis (see Materials and methods) with abundances at the genus level yielded two distinct clusters. Abundances were obtained with colored de Bruijn graphs. One was enriched in the genus Bacteroides while the other was enriched in the genus Prevotella. Principal component 1 was linearly correlated with the genus Prevotella while principal component 2 was linearly correlated with the genus Bacteroides. This analysis suggests that there is a continuum between the two abundant genera Bacteroides and Prevotella. This interpretation differs from the original publication in which three human gut enterotypes were reported . More recently, it has been proposed that there are only two enterotypes and individuals are distributed in a continuum between the two .
Boisvert et al. Genome Biology 2012 13:R122 doi:10.1186/gb-2012-13-12-r122