Quantitative Approach in the Study of Adhesion of Lactic Acid Bacteria to Intestinal Cells and Their Competition with Enterobacteria

Abstract
To describe the phenomena of bacterial adhesion to intestinal cells and the competition for adhesion between bacteria, mathematical equations based on a simple dissociation process involving a finite number of bacterial receptors on intestinal cell surface were developed. The equations allow the estimation of the maximum number ofLactobacillus sp. and Escherichia coli cells that can adhere to Caco-2 cells and intestinal mucus; they also characterize the affinity of the bacteria to Caco-2 cells and intestinal and fecal mucus and the theoretical adhesion ratio of two bacteria present in a mixed suspension. The competition for adhesion between Lactobacillus rhamnosus GG and E. coliTG1 appeared to follow the proposed kinetics, whereas the competition between Lactobacillus casei Shirota and E. coliTG1 may involve multiple adhesion sites or a soluble factor in the culture medium of the former. The displacement of the adheredLactobacillus by E. coli TG1 seemed to be a rapid process, whereas the displacement of E. coli TG1 by the Lactobacillus took more than an hour.