Viability and Survival of Lactobacillus acidophilus Soygurt in the Gastric of Rat

Abstract

Due to harsh environment that must be passed in digestive system, one of important characteristic of lactic acid bacteria is acid tolerance which leads an ability to survive in the gastric. In the current study, rat gastric was used to evaluate a viability and a survival of Lactobacillus acidophilus in soybean based soygurt. Preliminary in vitro study suggested that the growth of L. acidophilus was pH dependent. The soygurt containing 17.8 log10 CFU/mL of L. acidophilus was administered orally to the rats per day. After 7 days consecutive administration, the viability of L. acidophilus in gastric juice of rats was assessed. The protein profile and the presence of lactic acid in the gastric juice were analyzed. The result showed that 9.2 log10 CFU/mL of L. acidophilus was survived to pass in gastric. The pH of the gastric juice was more acidic in the presence of lactic acid after soygurt administration compared to control. The protein profile of juice contained specific protein with molecular mass about 100, 50, 37 kDa and small peptide which probably secreted as bacterial responses against gastric environment. These findings suggested that L. acidophilus in soygurt is viable and survived in gastric environment and this soygurt is qualified as an alternative probiotic for human, especially with lactose intolerance.