Table 4.

Cytotoxic effect of different concentrations of lyophilized supernatant of S. thermophilus cultures, expressed as percentage of HT-29 cancer cells remained viable after 48 h of incubation.

Supernatant concentration (μg/ml)	M17PTZA396	M17PTZA496	TH982	GG	M17 growth medium
125	75.0 ± 0.02	93.7 ± 0.02	98.3 ± 0.01	65.8 ± 0.01	98.2 ± 0.05
250	65.2 ± 0.04	78.0 ± 0.07	71.1 ± 0.03	63.9 ± 0.09	86.9 ± 0.06
500	58.4 ± 0.12	65.3 ± 0.05	71.0 ± 0.05	58.9 ± 0.02	88.3 ± 0.11
1000	45.5 ± 0.07	62.5 ± 0.04	58.5 ± 0.01	54.1 ± 0.02	84.7 ± 0.06
2000	43.4 ± 0.05	61.8 ± 0.01	58.7 ± 0.05	48.2 ± 0.02	89.2 ± 0.05
4000	40.2 ± 0.03	58.8 ± 0.02	54.7 ± 0.04	41.1 ± 0.03	90.5 ± 0.05
8000	37.6 ± 0.03	57.6 ± 0.01	46.0 ± 0.04	29.1 ± 0.02	88.8 ± 0.24

Lb. rhamnosus GG is the commercial reference probiotic strain. Growth medium M17 represents the negative control. A solution of 3% DMSO was used as positive control, which gave 26.2 ± 0.04 cell viability. Data are expressed as means ± SD.