In vitro evaluation of probiotic potential of Pediococcus pentosaceus L1 isolated from paocai—a Chinese fermented vegetable

This study aimed to investigate the probiotic potential of Pediococcus pentosaceus L1 isolated from paocai, a Chinese fermented vegetable. In vitro analysis revealed that P. pentosaceus L1 had the capability to tolerate simulated gastrointestinal juices. Adhesion of P. pentosaceus L1 to HT-29 intestinal epithelial cells (IEC) was also observed. L1 was sensitive to ampicillin, gentamycin, kanamycin, strepomycin, clindamycin, tetracycline and chloramphenicol. L1 showed effective inhibition against Escherichia coli, Salmonella typhimurium, and Shigella flexneri. P. pentosaceus L1 also exhibited the abilities of auto-aggregation and co-aggregation with Shigella flexneri. Pre-treatment of HT-29 IEC with P. pentosaceus L1 prior to tumor necrosis factor-alpha (TNFα) challenge down-regulated the expression of pro-inflammatory genes, such as IL8, CCL20, CXCL10, and CXCL1. The level of IL-8 released in culture supernatant of TNFα-challenged HT-29 IEC was reduced by strain L1, confirming the observed decrease in TNFα-induced IL-8 mRNA expression. These results indicate the probiotic potential of P. pentosaceus L1, and that this strain could be used to produce functional foods.