Factors Relating to Adhesion and Aggregation of Lactobacillus paracasei and Lactobacillus rhamnosus Strains

There is limited information concerning the effects of various factors on adhesion and auto- and co-aggregation of Lactobacillus strains derived from the human oral cavity. The objectives of this study were to investigate the effects of various factors, including enzymatic, chemical and physical pretreatments, on adhesion and aggregation abilities of 19 Lactobacillus paracasei and 18 Lactobacillus rhamnosus strains in H357 oral keratinocytes model. Such abilities of the potential probiotic strains, L. paracasei SD1 and L. rhamnosus SD11, were also compared to those of L. rhamnosus GG. Surface proteins were shown to be involved in adhesion of L. rhamnosus strains, whereas S-layer proteins, other proteins and carbohydrates were involved in the adhesion of L. paracasei. Proteins, glycoproteins, carbohydrates, and S-layer proteins were involved in bacterial aggregation. It suggests that bacterial adhesion is strain-specific, and may depend on its origin. Positive effects of amylase, lysozyme, Ca ions and low pH on adhesion and aggregation abilities were found in this study. The findings in this study may be useful for selecting the probiotic strains used for oral health, and thus for the development of probiotic products.