Toxicological Safety Assessment of Heat-Treated Lactiplantibacillus plantarum OLL2712 as a Food Ingredient

Lactiplantibacillus plantarum is a Gram-positive, bacilli-shaped bacterium commonly found in fermented foods and the human gastrointestinal tract. Heat-treatment of L. plantarum OLL2712 prior to consumption has been found to have positive health effects. However, a full toxicological evaluation of heat-treated L. plantarum OLL2712 cells (heat-treated OLL2712) has not been conducted. In this regard, heat-treated OLL2712 was evaluated for use as an ingredient in food and dietary supplements using a panel of toxicological tests including genotoxic and subchronic studies. Heat-treated OLL2712 did not show any genotoxicity based on an in vitro mammalian chromosomal aberration test and in vivo mouse micronucleus assay up to 8.0 × 10⁹ cells/mL and 6.4 × 10¹² cells/kg, respectively. In the acute oral toxicity study, no toxic effects were observed at 5 × 10¹¹ cells/kg body weight. In the 13-week subchronic toxicity study, rats were administered (via gavage) heat-treated OLL2712 at concentrations of 0.5 × 10¹¹, 1.5 × 10¹¹, and 5 × 10¹¹ cells/kg body weight. Administration did not significantly impact mortality, body weight, food consumption, ophthalmology, hematology, clinical chemistry, coagulation, urinalysis, and macroscopic or microscopic findings. The no-observed-adverse-effect level of heat-treated OLL2712 in both sexes was 5 × 10¹¹ cells/kg body weight/day, the highest dose tested.