Expanding the Use of Meat Bioprotective Carnobacterium maltaromaticum as Potential Probiotic for Human Consumption

This study evaluated the probiotic potential of three Carnobacterium maltaromaticum strains (CM_B824, CM_B827, and CM_B829) previously recognized for their bioprotective effects in meat products. The strains were characterized based on cell surface hydrophobicity, auto-aggregation, co-aggregation with foodborne pathogens, and their ability to inhibit pathogen adhesion to Caco-2 cells through competition, displacement, and exclusion assays. Survival under simulated gastrointestinal conditions and effects on Caco-2 cell viability (PrestoBlue assay) were also assessed. C. maltaromaticum strains exhibited exceptionally high cell surface hydrophobicity (~ 98% affinity to xylene and toluene), significantly outperforming the commercial control Lacticaseibacillus rhamnosus GG ATCC 53,101 (LR) (46% and 35%, respectively). While auto-aggregation was moderate (32% for CM vs. 53% for LR), the CM strains effectively reduced the adherence of Listeria monocytogenes, Salmonella spp., and E. coli O157:H7 to Caco-2 cells, with competition being the most effective inhibitory mechanism. Notably, CM_B824 demonstrated the strongest reduction in pathogen adherence. Furthermore, neither individual strains nor their combination (CM_pool) affected Caco-2 viability. Under simulated digestion, the CM_pool showed superior resilience compared to LR, maintaining higher survivability (88% vs. 66%) and viable counts (> 8 log CFU/g). These results indicate that the dual functionality of the CM strains, combining established bioprotective efficacy in food matrices with robust probiotic potential, positions them as versatile candidates for multifunctional food applications. Their ability to simultaneously enhance food safety and provide health benefits upon ingestion offers a significant strategic advantage for the functional food industry.