Characterization of exopolysaccharide (EPS) from Lactobacillus fermentum (TISTR 2514) and its potential prebiotic properties

The aims of this study were to characterize and investigate the prebiotic potential of exopolysaccharides (EPS) produced by Lactobacillus fermentum TISTR2514 from Thai-fermented food. The EPS showed a symmetrical sharp peak which separated using GPC technique and its molecular weight was 48.192 kDa. HPLC analyses presented that the EPS consisted of rhamnose, galactose, mannose and glucose. The prebiotic potential of EPS produced by L. fermentum TISTR2514 was studied. The results indicated that EPS can be resisted to artificial gastric juice at pH1 for 2h and to -amylase at pH7 for 6h, in the percent of more than 89 and 82%, respectively. Furthermore, these EPS could stimulate the growth of probiotics (L.rhamnosus DSM 20021 and L. casei DSM 20011 from log 6.02 0.08 to log 8.08  0.06 CFU/ml and from log 6.030.05 CFU/ml to log 8.170.02 in 24h, respectively), which was higher than using FOS. Bacterial enzyme assessment of a combination of probiotics and EPS-producing strain L. fermentum TISTR2514 (candidate prebiotic) revealed a greater reduction in -glucuronidase activity than using probiotics or EPS alone. The ability of synbiotic (probiotics and EPS) is particularly interesting for potentially reducing the-glucuronidase activity and for decreasing the risk of colorectal cancer, however further in-depth study is required.