Levan from Bacillus amyloliquefaciens JN4 acts as a prebiotic for enhancing the intestinal adhesion capacity of Lactobacillus reuteri JN101

Improving intrinsic adhesion performance of the known probiotics facilitates their residence and colonization, and therefore exerts more beneficial effects on the human or animal host. In this study, through adaptive culture with levan, Lactobacillus reuteri JN101 achieved the same biomass and exhibited 2.6 times higher adhesion capacity to HT-29 cells than those grown with glucose. The mechanism study related to this adhesion enhancement showed that the elevated proportion of unsaturated fatty acids facilitated the bacterial cells to overcome repulsive forces to approach the intestinal epithelial cell. At the same time, and the greater amounts of cell membrane proteins, such as S-layer protein (3.2 folds), elongation factor Tu (2.6 folds) and phosphoglycerate kinase (2.4 folds) probably enhanced the complementary interactions to the receptor on the epithelial cell. These results presented here indicated levan could be used as a potential prebiotic to regulate the adhesion capacity of probiotics, and provide ground for developing the specific-probiotics oriented functional food.