Resistance of the lactobacilli to pepsin under low pH was tested as described previously (Charteris et al. 1998). Briefly, bacterial cells from overnight (18 h) were harvested at 4 °C for 10 min (6000 × g), washed twice with PBS buffer (pH 7.3). Simulated gastric juice was prepared by suspending pepsin (0.3 mg/ml; Sigma) in PBS (pH 2.0).