title: Enhancement of the immune response against Salmonella infection of mice by heat-killed multispecies combinations of lactic acid bacteria.
abstract: Heat-killed lactic acid bacteria (LAB) has advantages over live LAB in that it has a long shelf-life and is therefore easy to store and transport. From four LAB strains selected by immunomodulatory activity and adherent properties, we prepared the heat-killed multispecies combination of LAB (MLAB) and the cell walls from MLAB under two conditions (100 °C for 30 min and 121 °C for 15 min). Different effects on the adherent properties of these four LAB strains were observed, depending on the heating conditions. With mouse macrophage cells, the two heat-killed MLABs (HMLABs) showed significantly higher induction activities on the production of interleukin 12 (IL-12) than their individual strains did. Heat-killed MLABs and cell-wall preparations were able to reduce the Salmonella invasion of Caco-2 and mouse macrophage cells. Feeding mice with HMLAB could inhibit the Salmonella invasion of mice significantly. For these mice, the expression level of pro-inflammatory cytokines, such as TNF-α and IL-6, in mouse serum was reduced while that of the anti-inflammatory cytokine, i.e. IL-10, was enhanced. The HMLABs developed in this study showed higher protective effect against Salmonella invasion either of Caco-2 cells or of mice, relative to the heat-killed lactobacilli, which consisted of Lactobacillus acidophilus strains selected at random. In conclusion, the HMLABs were potentially useful for the protection of mice against Salmonella infection and the induced inflammation.
authors.affiliation: Department of Food Science and Biotechnology, National Chung Hsing University, No. 250, Kuo Kuang Rd, Taichung County 40227, Taiwan, ROC.
authors.forename: Chih-Yuan
authors.initials: CY
authors.lastname: Chen
authors.affiliation: Department of Food Science and Technology, Hung-Kuang University, No. 34, Chung-Chi Rd, Taichung County 43302, Taiwan, ROC.
authors.forename: Hau-Yang
authors.initials: HY
authors.lastname: Tsen
authors.affiliation: Department of Food Science and Technology, Hung-Kuang University, No. 34, Chung-Chi Rd, Taichung County 43302, Taiwan, ROC.
authors.forename: Chun-Li
authors.initials: CL
authors.lastname: Lin
authors.affiliation: Department of Food Science and Technology, Hung-Kuang University, No. 34, Chung-Chi Rd, Taichung County 43302, Taiwan, ROC.
authors.forename: Chien-Ku
authors.initials: CK
authors.lastname: Lin
authors.affiliation: Department of Food Science and Technology, Hung-Kuang University, No. 34, Chung-Chi Rd, Taichung County 43302, Taiwan, ROC.
authors.forename: Li-Tsen
authors.initials: LT
authors.lastname: Chuang
authors.affiliation: Department of Food Science and Biotechnology, National Chung Hsing University, No. 250, Kuo Kuang Rd, Taichung County 40227, Taiwan, ROC.
authors.forename: Chin-Shuh
authors.initials: CS
authors.lastname: Chen
authors.affiliation: Department of Food Science and Technology, Hung-Kuang University, No. 34, Chung-Chi Rd, Taichung County 43302, Taiwan, ROC.
authors.forename: Yu-Cheng
authors.initials: YC
authors.lastname: Chiang
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000276:immunology*; D016207:Cytokines / Q000097:blood / Q000378:metabolism; D004847:Epithelial Cells / Q000276:immunology / Q000382:microbiology; D006358:Hot Temperature; D006801:Humans; D056546:Lactobacillales / Q000276:immunology*; D008264:Macrophages / Q000276:immunology / Q000382:microbiology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D012475:Salmonella / Q000276:immunology*; D012481:Salmonella Infections, Animal / Q000276:immunology / Q000517:prevention & control*; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000276:immunology
chemical_list: D001428:Bacterial Vaccines; D016207:Cytokines; D015164:Vaccines, Inactivated