Probiotic Properties of Lactobacilli and Their Ability to Inhibit the Adhesion of Enteropathogenic Bacteria to Caco-2 and HT-29 Cells

We evaluated the probiotic properties of lactic acid bacteria using resistance, safety, and functional assays. A preliminary subtractive screening of nineteen strains was performed based on their survival in simulated gastric and intestinal juice, and cell surface characteristics (hydrophobicity and auto-aggregation). Five strains were selected for further characterization, which included the assessment of their co-aggregation to pathogens, phenol tolerance, antimicrobial activity, and safety. Moreover, their adhesion to Caco-2 and HT-29 cells and the ability to inhibit pathogenic bacteria adhesion were evaluated. All strains had high (>= 80.0%) survival rates in gastric and intestinal juices. Among them, Lactobacillus brevis CCMA 1284, L. plantarum CCMA 0743, and L. plantarum CCMA 0359 exhibited higher hydrophobicity (95.33, 96.06, and 80.02%, respectively), while L. paracasei CCMA 0504 and L. paracasei CCMA 0505 had the highest auto-aggregation values (45.36 and 52.66%, respectively). However, these last two strains were positive for the DNAse test, which is a safety concern. The CCMA 0359 and CCMA 1284 strains did not show antimicrobial activity, while the CCMA 0505 strain had a higher percentage of adhesion (4.75%) to Caco-2 cells. In the simulated competition and exclusion assays, the CCMA 0743 strain was able to reduce Salmonella adhesion to both cells (Caco-2 and HT-29), but only the CCMA 0743 and CCMA 0505 strains inhibited Escherichia coli adhesion to HT-29 cells in the competition assay. According to the results of these evaluated attributes, this strain showed to be an excellent candidate for probiotic use.

Automated summary

The probiotic properties of lactic acid bacteria were evaluated using resistance, safety, and functional assays. Among the strains evaluated, some showed high survival rates in simulated gastric and intestinal juices, while others exhibited characteristics like hydrophobicity and auto-aggregation. This study identified specific strains that could be good candidates for probiotic use based on their assessed attributes.