Evaluation of probiotic properties of Lactobacillus plantarum strains isolated from Chinese sauerkraut

Lactobacillus plantarum strains isolated and identified from naturally-fermented Chinese sauerkraut were examined in vitro for potential probiotic properties and in vivo for cholesterol-lowering effect in mice. Among 7 isolated L. plantarum strains, strains S2-5 and S4-1 were found to possess desirable probiotic properties including ability to survive at pH 2.0 for 60 min, tolerate pancreatin and bile salts, adhere to Caco-2 cells, produce high β-galactosidase activity and antimicrobial activity against Escherichia coli O157 and Shigella flexneri CMCC(B). In addition, strains S2-5 and S4-1 were susceptible to several antibiotics, and capable of reducing cholesterol level in MRS medium by assimilation of cholesterol at 20.39 and 22.28 μg ml−1, respectively. The in vivo study with L. plantarum S4-1 showed that feeding with fermented milk containing this strain was able to effectively reduce serum cholesterol level in mice, demonstrating its potential as an excellent probiotic candidate for applications in functional products.