Toxicity Studies of Lactobacillus plantarum PS128 Isolated from Spontaneously Fermented Mustard Greens.

Probiotics are extensively available to consumers; however, the use of probiotics may not always be safe, and there are few reports on their side effects, including those of Lactobacillus. Lactobacillus plantarum strain PS128 isolated from spontaneously fermented mustard greens in Taiwan was recently reported to exhibit probiotic properties. In this study, we aimed to assess the safety of strain PS128 for use in humans via examining genotoxic and oral toxic effects using in vitro and in vivo testing. Five strains of Salmonella typhimurium were evaluated by the Ames test; no signs of increased reverse mutation were observed following exposure to PS128. Additional testing of Chinese hamster ovary (CHO) cells exposed to PS128 revealed that the incidence of chromosomal aberrations in CHO cells had not increased. PS128 treatment also did not affect the proportion of immature to total erythrocytes or the number of micronuclei in the immature erythrocytes of ICR mice. Moreover, following a 28 day study involving repeated oral dose toxicity tests (2400, 400, and 40 mg/kg body weight) utilizing an ICR mouse model, no observable adverse level (NOAEL) was found at any of the doses. PS128 was sensitive to antibiotics; however, genes related to the production of biogenic amines were absent. While further research is required, these toxicological assessments suggest that PS128 could be safe for human consumption.