Figure 1. Phylum level microbial compositions of faeces, lavage and tissue samples.

Biospeciemens from faeces (Costello [45], Turnbaugh [12] and Caporaso [11]), lavage samples (Tong) and tissue samples (Frank [21]) were compared. Only predominant phyla with relative abundances higher than 0.1% in Tong dataset were depicted in the bar graph, and the phyla with low abundances were grouped together. For Costello and Caporaso datasets, only the fractions of intestinal microbiota were shown here.