Adhesion Conditions of Bifidobacterium pseudocatenulatum KAKii to Human Enterocyte-like Caco-2 Cell Lines

Attachment ability of bifidobacteria strains to the human intestinal surface is an important criterion as a probiotic candidate. However, attachment activity is influenced by external and internal conditions. This study was conducted to screen cell surface hydrophobicity and adhesion scores of bifidobacteria strains. Attachment conditions (pH and exposure time) of selected strains to human enterocyte-like Caco-2 cell lines were subsequently investigated. Three different solvents (n-hexadecane, Toluene, and Xylene) were used in cell surface hydrophobicity analysis. Based on the results obtained, xylene presented consistent cell hydrophobicity activity in all strains used. Bifidobacterium pseudocatenulatum KAKii (wild type strain) gave promising cell hydrophobicity activity with no significant difference (p > 0.05) when compared to Lactobacillus plantarum NBRC 3070 with xylene as a solvent, and also presented a significantly higher attachment score (p < 0.05) compared to all strains used. The influence of pH and time exposure on adhesion of B. pseudocatenulatum KAKii to Caco-2 cells revealed that this strain was favored to attach to the intestinal cell line at pH 6 and after 120 min of exposure. Further optimization of attachment conditions will be carried out.