title: Comparative analysis of the gene expression profile of probiotic Lactobacillus casei Zhang with and without fermented milk as a vehicle during transit in a simulated gastrointestinal tract.
abstract: Studies have found that the survival of probiotics could be strongly enhanced with dairy products as delivery vehicles, but the molecular mechanism by which this might occur has seldom been mentioned. In this study, microarray technology was used to detect the gene expression profile of Lactobacillus casei Zhang with and without fermented milk used as a delivery vehicle during transit in simulated gastrointestinal juice. Numerous genes of L. casei Zhang in strain suspension were upregulated compared to those from L. casei Zhang in fermented milk. These data might indicate that L. casei Zhang is stimulated directly without the protection of fermented milk, and the high-level gene expression observed here may be a stress response at the transcriptional level. A large proportion of genes involved in translation and cell division were downregulated in the bacteria that were in strain suspension during transit in simulated intestinal juice. This may impede protein biosynthesis and cell division and partially explain the lower viability of L. casei Zhang during transit in the gastrointestinal tract without the delivery vehicle.
authors.affiliation: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Department of Food Science and Engineering, Inner Mongolia Agricultural University, Huhhot, Inner Mongolia 010018, PR China. imwjc@163.com
authors.forename: Jicheng
authors.initials: J
authors.lastname: Wang
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zhong
authors.forename: Wenyi
authors.initials: W
authors.lastname: Zhang
authors.forename: Qiuhua
authors.initials: Q
authors.lastname: Bao
authors.forename: Aibin
authors.initials: A
authors.lastname: Wei
authors.forename: He
authors.initials: H
authors.lastname: Meng
authors.forename: Heping
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001826:Body Fluids / Q000382:microbiology; D041981:Gastrointestinal Tract / Q000382:microbiology*; D020869:Gene Expression Profiling; D006801:Humans; D007780:Lacticaseibacillus casei / Q000235:genetics* / Q000502:physiology*; D046228:Microarray Analysis; D050296:Microbial Viability; D008892:Milk / Q000382:microbiology*; D008962:Models, Theoretical; D019936:Probiotics; D013312:Stress, Physiological