Characterization of Lactiplantibacillus plantarum subsp. plantarum and Bifidobacterium animalis spp. lactis BB-12 postbiotics: In vivo and in vitro experiments against foodborne pathogens

This study aimed to assess the antimicrobial properties of Lactiplantibacillus plantarum subsp. plantarum (P-Lp) and Bifidobacterium animalis spp. lactis BB-12 (P-BB12) postbiotics against foodborne pathogens, with a specific focus on the inhibition of Salmonella Typhimurium in chicken breast during storage at 4 ◦ C. The study used agar well diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays, which revealed a dose-dependent effect of postbiotics on foodborne pathogens. The antioxidant activity of the postbiotics was evaluated via DPPH (2,2-diphenyl-1-picrylhydrazyl) and ferric ion-reducing antioxidant poten- tial (FRAP) assays. These results indicated the potential of postbiotics to protect against oxidative stress. In addition, proton nuclear magnetic resonance (1H NMR) was used to characterize postbiotics identifying approximately thirty-nine potential biomarkers of postbiotic metabolites, including fatty acids, organic acids, carbohydrates, amino acids, and alcohols. In vivo tests revealed that after 10 days of storage at 4 ◦ C, chicken breast treated with various concentrations of these postbiotics had lower counts of S. Typhimurium compared to untreated controls. Combining different postbiotics resulted in synergistic effects that enhanced their benefits against pathogens.