Real-time PCR evaluation of 16S rrn operons of Bifidobacterium (A), B. longum (B), Lactobacillus (C) and L. helveticus (D) related to the time points (T0 and T1) of the feeding study. Data are expressed as number of operons in 1 μg of total bacterial DNA extracted from the feces. The box represents the interquartile range (25-75th percentile) and the line within the box is the median value. The bottom and top bars indicate the 10th and 90th percentiles, respectively. Outlier values are indicated (black circles). * indicates a significant difference (P < 0.05).