FIG 6.
Transepithelial electrical resistance (TEER) of L. rhamnosus GG and the starter culture as frozen product and in yogurt. (A) TEER of Caco-2 cell monolayers stimulated with frozen pellets of the starter culture (Frozen St + Lb), frozen pellets of L. rhamnosus GG (Frozen Lr GG [F_start]), or a combination of the two samples (Frozen St + Lb + Lr GG). In addition, yogurt containing only the starter culture (Yogurt St + Lb) and yogurt cofermented with L. rhamnosus GG on the day of production (Yogurt Day 1 St + Lb + Lr GG [Y-1_F_start]) and by end of shelf life (Yogurt Day 28 St + Lb + Lr GG [Y28_F_start]) were included in the experiment. The final concentrations used for all samples were 2 × 108 CFU/ml and 4 × 107 CFU/ml for the starter culture and L. rhamnosus GG, respectively. (A) The y axis shows the percent change in TEER relative to the baseline, which is the TEER reading just prior to adding the bacterial strains (time = 0 h). The x axis shows the time in hours. Each data point represents the mean ± SD of results from technical triplicates. (B) Area under the curve (AUC) of TEER measurements from 0 to 20 h relative to the baseline (100%) (y axis) for the measurement presented in panel A. Each bar represents the mean ± SD for technical triplicates. One-way ANOVA followed by Tukey’s test was performed, and statistically significant differences are shown.