Figure 2

Intestinal microbiota profiles across Clostridium difficile infection (CDI) cases and control subjects. The heatmap shows the abundance of V1-V3 sequences by bacterial family (rows) across all patients (columns). Sequence counts were normalized in order to obtain an equivalent number of reads for each sample. The dendrogram shows hierarchical clustering (unweighted pair group method with arithmetic mean) of microbial communities using Canberra distance metric. The bar on the top indicates disease status for each patient: cases (n = 25) are in red and controls (n = 25) are in blue. Patients with the lowest degree of intestinal biodiversity (n = 6; all of these patients are cases) are marked with an asterisk. The staggered bars on the left indicate phylum affiliations: Ba, Bacteroidetes; Fi, Firmicutes; Pr, Proteobacteria; Ac, Actinobacteria; Ve, Verrucomicrobia; Fu, Fusobacteria. Other phyla (Lentisphaerae, Spirochaetes, Synergistetes, Tenericutes, Cyanobacteria and TM7) and reads that were unclassified at the phylum level, which altogether represent ≤6.3% of the reads/patient, are not depicted. Relevant bacterial families are listed on the right of the figure. The color gradient is proportional to the logarithm of sequence abundance from 0 to 1,044 reads, as indicated by the scale.