This study evaluated the probiotic potential of Lactococcus lactis strains isolated from natural whey starter cultures used in artisanal cheese production. The strains were tested for survival in simulated gastric juice, bile tolerance, hydrophobicity, auto- and co-aggregation, and their ability to inhibit the adhesion of pathogenic bacteria to epithelial cells. The results showed that some strains exhibited high hydrophobicity and auto-aggregation, and low co-aggregation with pathogenic strains. Safety parameters, including antibiotic susceptibility and haemolytic activity, confirmed the safety of all strains. Four promising strains were tested for their ability to inhibit the adhesion of enteroinvasive Escherichia coli (EIEC) and Salmonella Typhimurium to epithelial cells. The strains A3-A5-I4-I7 demonstrated the ability to compete with pathogens and exert a protective effect on cells previously infected with E. coli or S. Typhimurium. The study highlights the potential of these L. lactis strains as probiotics, which could be used to develop novel functional foods with health benefits. The findings suggest that these strains could be valuable for improving gut health and preventing pathogen colonization.This study evaluated the probiotic potential of Lactococcus lactis strains isolated from natural whey starter cultures used in artisanal cheese production. The strains were tested for survival in simulated gastric juice, bile tolerance, hydrophobicity, auto- and co-aggregation, and their ability to inhibit the adhesion of pathogenic bacteria to epithelial cells. The results showed that some strains exhibited high hydrophobicity and auto-aggregation, and low co-aggregation with pathogenic strains. Safety parameters, including antibiotic susceptibility and haemolytic activity, confirmed the safety of all strains. Four promising strains were tested for their ability to inhibit the adhesion of enteroinvasive Escherichia coli (EIEC) and Salmonella Typhimurium to epithelial cells. The strains A3-A5-I4-I7 demonstrated the ability to compete with pathogens and exert a protective effect on cells previously infected with E. coli or S. Typhimurium. The study highlights the potential of these L. lactis strains as probiotics, which could be used to develop novel functional foods with health benefits. The findings suggest that these strains could be valuable for improving gut health and preventing pathogen colonization.