In-vitro study of Limosilactobacillus fermentum PCC adhesion to and integrity of the Caco-2 cell monolayers as affected by pectins

Abstract

• Adhesion of L. fermentum PCC to Caco-2 cells was effected by pectins. • L. fermentum PCC and in combination with pectins increase TEER across the monolayer. • Increases in TEER are related to the differential expression of the TJ genes. This study investigated the effect of four citrus pectins on adhesion of the probiotic Limosilactobacillus fermentum PCC and integrity of the intestinal epithelial monolayers using the Caco-2 cell model. Adhesion of L. fermentum PCC was enhanced (from 35% to 54–73%) in the presence of pectins with high and moderate degree of esterification (DE), whereas it was reduced (to 2%) by a pectin with low DE. Transepithelial electrical resistance (TEER) was significantly increased upon exposure to L. fermentum PCC alone (by 33%) and, to a greater extent, by combinations with pectins (by 44 – 48%), suggesting synergistic action of bacteria and pectins. Increases in TEER were related to transcriptional responses of the tight junction genes, encoding claudin-4 and claudin-2 proteins. The overall results indicated that pectins, when applied in synbiotic combination with L. fermentum PCC, have potential to improve bacterial adhesion and the intestinal epithelial barrier.