Exopolysaccharides of Lactobacillus reuteri: Their influence on adherence of E. coli to epithelial cells and inflammatory response

• EPS-DSM 17938 are high Mw linear d-glucan, which increased IL-1β gene expression.
• Branched high Mwd-glucan EPS-L26 exerted up-regulation of NF-κB, TNF-α and IL-6 mRNA.
• The both EPS inhibit enterotoxigenic E. coli (ETEC) adhesion on IPEC-1 cells.
• Moreover, both EPS inhibit ETEC-induced up-regulation of IL-1β mRNA.

The aim of the study was to characterize exopolysaccharides (EPS) originated from Lactobacillus reuteri strain DSM 17938 (EPS-DSM17938) and L. reuteri strain L26 Biocenol™ (EPS-L26) and evaluate their influence on adherence of enterotoxigenic Escherichia coli (ETEC) to IPEC-1 cells and proinflammatory gene expression. Both EPS were d-glucan polysaccharides with higher molecular weight (Mw), but differing in spatial conformation and elicited variable cytokine profile. EPS-DSM17938, relatively linear polysaccharide with (1 → 4) and (1 → 6) glycosidic linkages, increased IL-1β gene expression (0.1 mg/mL; P < 0.05), while EPS-L26, more branched polysaccharide with (1 → 3) and (1 → 6) glycosidic linkages, exerted slight but statistically significant up-regulation of NF-κB, TNF-α and IL-6 mRNA (P < 0.05). The most significant finding is that preincubation of IPEC-1 cells with both EPS followed by ETEC infection inhibit ETEC adhesion on IPEC-1 cells (P < 0.01) and ETEC-induced gene expression of proinflammatory cytokine IL-1β and IL-6 (P < 0.01).