title: Evaluation of probiotic characteristics of newly isolated Lactobacillus spp.: immune modulation and longevity.
abstract: In the current study, the probiotic potential of approximately 350 strains of lactic acid bacteria isolated from Korean infant feces and Kimchi was investigated. Common probiotic properties of the bacterial strains, such as acid tolerance, bile tolerance and adhesion to human intestinal epithelial cells (HT-29 cells), were examined. Some strains were found to have immune modulatory and antimicrobial properties. Antagonistic activity against a panel of pathogenic bacteria was found to be strain dependent. To evaluate the immune modulatory activity of the strains, lymphocyte interferon (IFN)-γ secretion was determined in conjunction with cell proliferation. Some strains of Lactobacillus gasseri, L. fermentum and L. plantarum exhibited increased IFN-γ levels and lymphocyte proliferation. To evaluate the effects of these immune modulating lactobacilli on host life span, Caenorhabditis elegans was used as an in vivo model. Nematodes that were supplied heat-killed lactobacilli as a food source exhibited obvious differences in life span compared with those fed Escherichia coli OP50. The mean life span (determined as mean percent survival) of worms fed L. plantarum CJLP133 and L. fermentum LA12 was 13.89% and 13.69% greater, respectively, than that of control nematodes after 21 days (P=0.036 and 0.043, respectively). In addition, some of safety profiles, including hemolytic type, gelatin hydration and degradation of urea, were found to be positive. These newly identified lactobacilli hold promise for use as probiotic agents, feed additives and/or in food applications.
authors.affiliation: Division of Food Bioscience and Technology, College of Life Sciences and Biotechnology, Korea University, Seoul, 136-701, Republic of Korea.
authors.forename: Jin
authors.initials: J
authors.lastname: Lee
authors.forename: Hyun Sun
authors.initials: HS
authors.lastname: Yun
authors.forename: Kyu Won
authors.initials: KW
authors.lastname: Cho
authors.forename: Sejong
authors.initials: S
authors.lastname: Oh
authors.forename: Sae Hun
authors.initials: SH
authors.lastname: Kim
authors.forename: Taehoon
authors.initials: T
authors.lastname: Chun
authors.forename: Bongjoon
authors.initials: B
authors.lastname: Kim
authors.forename: Kwang Youn
authors.initials: KY
authors.lastname: Whang
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D017173:Caenorhabditis elegans / Q000254:growth & development* / Q000276:immunology / Q000382:microbiology; D049109:Cell Proliferation; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli; D005243:Feces / Q000382:microbiology; D005516:Food Microbiology; D019073:HT29 Cells; D006801:Humans; D007223:Infant; D007371:Interferon-gamma / Q000378:metabolism*; D007778:Lactobacillus / Q000235:genetics / Q000302:isolation & purification*; D008136:Longevity; D019936:Probiotics / Q000032:analysis*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014675:Vegetables / Q000382:microbiology
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D007371:Interferon-gamma