title: Screening of Immune-Active Lactic Acid Bacteria.
abstract: The purpose of this study was to investigate the effect of lactic acid bacteria (LAB) cell wall extract on the proliferation and cytokine production of immune cells to select suitable probiotics for space food. Ten strains of LAB (Lactobacillus bulgaricus, L. paracasei, L. casei, L. acidophilus, L. plantarum, L. delbruekii, Lactococcus lactis, Streptococcus thermophilus, Bifidobacterium breve, and Pedicoccus pentosaceus) were sub-cultured and further cultured for 3 d to reach 7-10 Log colony-forming units (CFU)/mL prior to cell wall extractions. All LAB cell wall extracts failed to inhibit the proliferation of BALB/c mouse splenocytes or mesenteric lymphocytes. Most LAB cell wall extracts except those of L. plantarum and L. delbrueckii induced the proliferation of both immune cells at tested concentrations. In addition, the production of TH1 cytokine (IFN-γ) rather than that of TH2 cytokine (IL-4) was enhanced by LAB cell wall extracts. Of ten LAB extracts, four (from L. acidophilus, L. bulgaricus, L. casei, and S. thermophiles) promoted both cell proliferating and TH1 cytokine production. These results suggested that these LAB could be used as probiotics to maintain immunity and homeostasis for astronauts in extreme space environment and for general people in normal life.
authors.affiliation: Department of Microbial Engineering, Konkuk University, Seoul 143-701, Korea.
authors.forename: E-Nam
authors.initials: EN
authors.lastname: Hwang
authors.affiliation: Department of Microbial Engineering, Konkuk University, Seoul 143-701, Korea.
authors.forename: Sang-Mo
authors.initials: SM
authors.lastname: Kang
authors.affiliation: Department of Food Science and Nutrition, Anyang University, Anyang 430-714, Korea.
authors.forename: Mi-Jung
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Central Institute, RION Co., Ltd., Jeonju 561-843, Korea.
authors.forename: Ju-Woon
authors.initials: JW
authors.lastname: Lee
keywords: TH1 cytokine IFN-γ; TH2 cytokine IL-4; cell wall extracts; lactic acid bacteria; proliferation