A preliminary safety evaluation of seven strains of lactic acid bacteria isolated from mare’s milk and its products

Abstract:

[Objective] The safety assessment of 7 strains of lactic acid bacteria (Enterococcus spp.) isolated from mare? s milk and its products (koumiss) was investigated in a mice feeding trial. Acute toxicity, thirty days feeding and bacterial translocation were conducted. [Methods] Different dose of Enterococcus JHZ9, JHZ15, JHZ17, JHZ22, JHZ25, JHZ28 and JNN1 were administrated to treatment groups separately by gavage for 7 days and 30 days, while the general appearances, body weight and food consumption were observed and recorded daily. Mice were killed after 30 days and the kidney, spleen, liver, heart and lungswere observed and weighted, then collected for bacterial translocation experiment. [Results] Except that test bacterial strains JHZ17 in the high dose group had significant difference with control group (P<0.05). In both acute toxicity and thirty days feeding experiments, no significant differences (P>0.05) were found between the treatment group and the control group in the weight of mice, food intake and the internal organ (heart, liver, spleen, lung and kidney) indices. The maximum tolerated dose (MTD) of acute toxicity is higher than 1010 CFU/(mL bw) 20 mL/(kg·d), within the range of non-toxic. No bacterial translocation was observed. [Conclusion] Lactic acid bacteria JHZ9, HZ15, JHZ17, JHZ22, JHZ25, JHZ28 and JNN1 have no toxicity and side effects.

Key words:Lactic acid bacteria, Acute toxicity, Thirty days feeding, Bacterial translocation