Safety evaluation of Bifidobacterium animalis subsp. lactis BLa80 under in vitro, and in vivo conditions

Bifidobacterium animalis subsp. lactis BLa80 is a new probiotic strain with extensive applications in food products both domestically and internationally. Given the rising consumption of this probiotic, its safety assessment is increasingly crucial in the food industry. This study evaluates the safety of strain BLa80 using a combination of in vitro and in vivo assays along with genomic analysis. Methods included exposing the strain to artificial gastric and intestinal fluids, as well as a medium containing bile salts, to stimulate human digestive conditions. The strain showed high tolerance to gastric fluid at pH of 2.5 and to 0.3% bile salts. It maintained a 99.92% survival rate in intestinal fluid. Additional tests assessed hemolytic activity, antibiotic susceptibility (revealing sensitivity to 7 antibiotics), and biogenic amine production using HPLC-ELSD, confirming the absence of histamine, and other harmful amines. Bile salt hydrolase activity was demonstrated qualitatively, and metabolic byproducts were quantitatively analyzed using a D-/L-lactic acid assay kit, showing that BLa80 produces 1.48 mg/mL of L-lactic acid and no harmful D-lactic acid. Genomic analysis confirmed the absence of virulence or pathogenicity genes, and a 90-day oral toxicity study in rats confirmed no toxic effects at various doses. Overall, these findings support the safety classification of the strain BLa80.