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 potential (FRAP) assays. These results indicated the potential of postbiotics to protect against oxidative stress. In addition, proton nuclear magnetic resonance ( 1 H 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. • Combination of postbiotics showed a potential antimicrobial and antioxidant effect. • H NMR spectroscopy confirmed bioactive compounds in the examined postbiotics. • The postbiotics reduced the viable count of S. Typhimurium in chicken breast meat.