Effect of cereal extracts and cereal fiber on viability of Lactobacillus plantarum under gastrointestinal tract conditions

Abstract

New probiotic foods are expected to develop out of the increasing demand for a health-oriented society. Fermented cereal has recently been looked to as a way of delivering lactic acid bacteria. The present study investigated the effect of cereal extracts and cereal fiber on the viability of the lactic acid bacterium Lactobacillus plantarum under gastrointestinal tract conditions, with simulated gastric juice and bile juice used for the evaluation of gastrointestinal tolerance. The cells were cultured using cereal media that contained cereal extract and cereal fiber to immobilize the cells. Malt and barley were used as cereal. Malt and barley extracts were also used to examine the effect of cereal extracts on gastrointestinal tolerance. Regarding gastric tolerance, the addition of cereal extracts significantly improved the viability of L. plantarum while immobilization within cereal fiber slightly improved its viability. The effect of malt extract was more positive than that of barley extract. Meanwhile, immobilization within cereal fiber played a major role in bile tolerance and the presence of cereal extracts further enhanced the tolerance of L. plantarum to bile juice. In both cereal media, cell immobilization within cereal fiber and the presence of cereal extracts had a synergistic effect on the gastrointestinal tolerance.