Project description:The survival of probiotics could be strongly enhanced by delivery vehicles, but the mechanism was unknown. In this study, whole genome microarray technology was used to detect the gene expression profiles of probiotic Lactobacillus casei Zhang in the absence and presence of fermented milk in simulated gastrointestinal tract. The results showed the gene expression profiles were significantly different under these two different conditions. The change of the gene expression profile may be helpful to comprehend the role of delivery vehicles in enhancing the survival of probiotics. Twelve samples of bacterial cells in the absence and presence of fermented milk were collected at 3 h in simulated gastric juice, 4 h and 8 h in intestinal juice, 2 biological replicates were obtained in each time point. The average of the normalized expression values of the 2 biological replicates for each probe was regarded as the expression value of a predicted gene. To identify the expression pattern of each gene across different treatments, n-fold change ratios were calculated for every gene in pure L. casei Zhang versus L. casei Zhang in fermented milk.
