Bile salt hydrolase can improve <i>Lactobacillus plantarum</i> survival in gastrointestinal tract by enhancing their adhesion ability

Abstract

Lactic acid bacteria (LAB) are major probiotics in food supplements. Survival in gastrointestinal (GI) tract is important for the effective use of LAB as probiotics. Bile salt hydrolase (BSH), which catalyzes the conversion of conjugated bile salts into free bile salts, can significantly modulate the gut microbiome. Here, we hypothesize that BSH is important for LAB survival and adhesion in the gut. The aim of this study is to investigate the effect of BSH on the survival of LAB in the GI tract. A panel of bsh genes from murine gut microbiota were amplified, cloned and expressed into Lactobacillus plantarum, which were then administered to mice by gavage. Our data indicated that the survival of BSH-positive L. plantarum was significantly prolonged in the GI tract compared with wild type L. plantarum. Furthermore, BSH-positive strains exhibited increased adhesion to Caco-2 intestinal cells than BSH-deleted L. plantarum. Enhanced adhesion to intestinal cells of BSH positive LAB can therefore be an important criterion for selecting effective probiotic strains in food industry.