Genomic features, safety assessment, and functional evaluation of Weissella bombi Y133 for potential probiotic applications

Weissella bombi Y133, isolated from Chinese traditional fermented fish, was characterized to evaluate its genomic features, safety, and probiotic potential. The complete genome (1.91 Mb) encoded diverse metabolic pathways and carbohydrate-active enzymes, indicating strong metabolic adaptability. No concerning antibiotic resistance or virulence genes were detected, and phenotypic assays confirmed the absence of hemolysis and biogenic amine production. W. bombi Y133 exhibited high tolerance to acid, bile salts, and phenol stress, along with strong auto-aggregation and co-aggregation capacities. Metabolomic profiling revealed extensive amino-acid and organic-acid biosynthesis without toxic metabolites. Cytotoxicity assays showed no adverse effects on RAW264.7 cells at supernatant concentrations ≤10%. In a 28-day oral study, W. bombi Y133 caused no physiological abnormalities and significantly reduced serum TNF-α and IL-6 levels while increasing IL-4 . Overall, W. bombi Y133 exhibits a favorable safety profile and promising potential as a probiotic strain. • Weissella bombi Y133 shows a safe genome without virulence or resistance genes. • The strain exhibits strong stress tolerance and aggregation abilities. • In vivo and in vitro assays demonstrate anti-inflammatory potential and safety.