Cholesterol-lowering effects and safety assessment of Lactobacillus spp. in vivo and in vitro testing for human use as probiotic from the dairy product in Egypt

BACKGROUND: The toxicity profile of lactobacilli may be strain dependent, so it should be considered for safe utilization of probiotics. Further, in vivo studies are necessary to evaluate their safety. RESULT: The ability of various probiotic strains to hydrolyze bile salts has been confirmed without noticeable hemolytic activity. Results revealed the presence of α-glucosidase, β-glucosidase, α-galactosidase, and β-galactosidase activity in all investigated isolates, while none of the isolates produced the carcinogenic enzyme β-glucuronidase. The probiotic strains exhibited remarkable cholesterol-lowering impact. Also, we found no evidence of chronic toxicity under the experimental conditions based on gross pathological examination of the viscera and study of the spleen and liver weight ratios. These findings indicated that the investigated strains, either alone or combined with their metabolites, had no obvious adverse effect on the mice's general health status. CONCLUSION: There is prove that the investigated probiotic strains are safe to be utilized for enhancing of the growth performance and are free of adverse side effects.