Lactic Acid Bacteria in Kimchi Might Be a Cause for Carcinogen Production in Intestine

ABSTRACT The objective of this study was to evaluate if kimchi may be related to carcinogenesis by evaluating the activities of β-glucuronidase and β-glucosidase of lactic acid bacteria isolated from kimchi, which play a role in carcinogenesis. Thirty-six lactic acid bacteria (22 Lactobacillus spp., 11 Pediococcus pentosaceus, 2 Leuconostoc spp., and 1 Weisella cibaria) isolated from various kimchi were incubated in 10 mL of lactobacilli MRS broth at 35oC for 20 h. Following incubation, 100 μL of each culture was suspended in 10 mL phosphate-buffered saline. The suspensions of 36 lactic acid bacteria strains were diluted with distilled water until OD500=1.048, and 65 μL aliquots of the suspensions were inoculated into the wells, where contained substrates to evaluate the activities of β-glucuronidase and β-glucosidase, followed by incubation at 35oC for 4 h for the enzyme reactions. Of 36 isolates, 19 strains (52.8%) produced β-glucuronidase, 3 strains (13.9%) produced β-glucosidase, and two strains (5.6%) produced both enzymes. This result indicates that consumption of kimchi may have a potential possibility for a carcinogen production in the gut by producing the pro-carcinogenic enzymes (β-glucuronidase, β-glucosidase) of the lactic acid bacteria in kimchi.