Safety assessment of lactic acid bacteria for human use / Mohd Syafiq Mokhtar

Nowadays, Lactic Acid Bacteria (LAB) such as probiotic have been widely used in commercial food products and consumed by people in many countries. Many reports have been published regarding the benefits and advantages of probiotic in recent years. However, there are also issues on the safety of probiotic that has raised concern among the public. This research project was primarily carried out evaluate the toxicity of Lactic Acid Bacteria (LAB) in human. A Lactic Acid Bacteria strain (LAB 8) was recultivated and grown in sterile deMan-Rogosa-Sharpe (MRS) broth. After freeze drying process, the LAB sample was administered orally to groups of mice with different doses for each groups (5 x 10⁸, 2 x 10⁹, and 1 x 10¹⁰ cfu/mice per day). The mice were observed for behavioural changes, sign of toxicity and mortality throughout the 14-days of post-dosing period. At day 14, the mice were killed and organs were then removed for gross examinations. No noticeable behavioural, activity changes or treatment-related illness occurred throughout the experiment period in all mice. No obvious changes was observed macroscopically on the visceral organs of the mice. No incidence of bacteremia occurred as there was no significant incidence of bacterial translocation into liver, spleen and blood. This present study indicates that LAB 8 is safe to be used as a probiotic. However, toxicity study on more animals need to be conducted to confirm the findings of this study.