Effect of apple extracts and selective polyphenols on the adhesion of potential probiotic strains of Lactobacillus gasseri R and Lactobacillus casei FMP

We aimed to investigate the influence of apple extracts (pulp and peel) and their phenolic constituents on the adhesion of two lactobacillus strains to Caco-2 and HT29-MTX intestinal epithelial cells, which were used as models of gastrointestinal tract mucosa. Apple pulp extracts (10 and 20 mu g/mL) decreased Lactobacillus gasseri R adhesion by 39.7% (P < 0.05) and 45.9% (P < 0.05), and Lactobacillus casei FMP adhesion by 6.8% and 19.4%, respectively. In contrast, apple peel (10 mu g/mL) enhanced L. gasseri R adhesion by 35.7% (P < 0.05) and L. casei FMP adhesion by 28.2% (P < 0.05). Apple peel at 20 mu g/mL increased the adhesion of both strains. Phenolic profiles of the extracts were characterised using high-resolution and accurate mass quantitative analysis; procyanidin B2 and chlorogenic acid were the main constituents. When tested individually, all the phenolics increased the adhesion of both lactobacilli. Our data indicated that apple peel and its phenolic constituents affected the microbiota-epithelium interaction. (C) 2017 Elsevier Ltd. All rights reserved.