Toxicity Studies of Lactobacillus plantarum PS128^TM 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^TM 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^TM 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^TM. Additional testing of Chinese hamster ovary (CHO) cells exposed to PS128^TM revealed that the incidence of chromosomal aberrations in CHO cells had not increased. PS128^TM 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^TM 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^TM could be safe for human consumption.