Number of phylotypes and genera as function of the total number of sequences. A. Rarefaction curves of individual samples. Curves were generated at the 97%-ID cutoff using RDP pyrosequencing pipeline . The three samples from the same subject are represented by the same colour. B. Rarefaction curves of the pooled dataset. OTUs with ≥97%, ≥95% and ≥90% pairwise sequence identity generated using RDP pyrosequencing pipeline  are arbitrarily assumed to form the same species, genus and family respectively. C. Number of genera. Taxonomic composition was identified using MG-RAST. The three samples from the same subject are represented by symbols of the same colour.