Subchronic oral toxicity assessment of Bacillus velezensis strain BV379 in sprague-dawley rats.

Introduction: The spore-forming bacterial species Bacillus velezensis is commonly utilized in feed for livestock and aquaculture. In recent years, there has been increased interest in introducing B. velezensis into human supplements and food. Before it can be safely administered in humans, the safety of each B. velezensis strain needs to be established. The objective of this study was to evaluate the in vivo safety of Bacillus velezensis strain BV379 by high-dose oral administration to rats in a 28-day subchronic toxicity study.

Methods: In this study, 80 animals were assigned to four groups: vehicle control, 1 × 10¹⁰, 4 × 10¹⁰, or 10 × 10¹⁰ CFU/kg bw/day by gavage. The following toxicological assessments were performed: ophthalmological examinations; observations for viability, signs of gross toxicity, and behavioral changes; in-life parameters, including body weight and food consumption; urinalysis, hematology, clinical chemistry, and coagulation assessments; macroscopic and microscopic tissue assessments; and bacterial enumeration in selected tissues.

Results: Under the conditions of this study, no adverse clinical endpoints were attributed to the administration of Bacillus velezensis strain BV379, which was well-tolerated up to the highest dose of 10 × 10¹⁰ CFU/kg bw/day.

Conclusion: These results support the in vivo pre-clinical safety of Bacillus velezensis strain BV379 for use in food and supplements.