Lactobacillus strains belonging to Casei group display various adherence to enterocytes and mucus.

Background. The ability of lactobacilli to adhere to the surface of the intestine is an important functional characteristic which can largely determine the effective colonization of the intestinal tract by probiotics. The following study compares the adhesion effi ciency of the twenty strains of Lactobacillus genus belonging to Casei group to the Caco-2 cells and gastrointestinal mucus. Material and methods. Twenty isolates of lactobacilli belonging to Casei group were tested. The ability of bacterial cells to adhere to mucus was examined using adhesion assay to gastrointestinal mucus. Obtained results were compared with adhesion effi ciency to Caco-2 cells. Phylogenetic relationship between isolates was analysed by rep-PCR. Results. The results showed large differences in adhesion effi ciency between strains, as well as differences in the effi ciency of adhesion to the intestinal epithelial cells and mucus. Group similarity highlighted by a repPCR technique does not correspond with groups of similarity in terms of the characteristics of the ability to adhere to mucus or the epithelial cells of intestinal tract. Conclusions. Strains having a high adhesion effi ciency to enterocytes do not always show a high adhesion effi ciency to the mucus. This may indicate the presence of different and multiple factors responsible for adhesion effi ciency of Lactobacillus group Casei strains to epithelial cells and mucus.