PCA analysis of samples from Experiment A. Principal Component Analysis of DGGE profiles of bacterial rRNA genes present in fecal samples from rat fed with control diet (green) or 10 g apples a day (red), respectively. A: Uninitiated animals. The amount of variability accounted for by Factor X is 25.0%, by Factor Y 16.2% and by Factor Z 13.6%. B: DMH initiated animals. The amount of variability accounted for by Factor X is 31.6%, by Factor Y 14.3% and by Factor Z 12.0%. Comparison of initiated and uninitiated animals by PCA revealed no grouping related to DMH initiation.