Potential prebiotic properties of exopolysaccharides produced by a novel<i>Lactobacillus</i>strain,<i>Lactobacillus pentosus</i>YY-112

Abstract

Exopolysaccharides (EPSs) derived from <i>Lactobacilli</i> have important physiological effects and are commonly used as new prebiotics. We identified and studied a new <i>Lactobacillus</i> strain, YY-112, isolated from waxberry (<i>Myrica rubra</i>). This strain, identified as <i>Lactobacillus pentosus</i>, tolerates acids, bile salts, and artificial digestive fluids. The EPS derived from this strain weighed 5.9 × 10⁴ Da and contained glucose, mannose, glucosamine, galactose, and rhamnose at 62.69 : 85.85 : 2.46 : 2.92 : 1.00 molar ratios. We found that the EPS from this strain increased the ratio of Bacteroidetes to Firmicutes and decreased the relative abundance of Proteobacteria, especially <i>Escherichia-Shigella</i>, when added to a simulated gastrointestinal system <i>in vitro</i>. After analysing the short-chain fatty acids, we found that this EPS promoted the production of acetic acid, propionic acid, and butyric acid, and reduced the ratio of acetic acid to propionic acid. We conclude that <i>Lactobacillus pentosus</i> YY-112 is a potential probiotic strain with EPS that is beneficial for the intestinal microbiota and short-chain fatty acid production.