Korea University · Biochemistry, Genetics and Molecular Biology
Professor Young-Hee Lim's research lab focuses on the discovery and functional characterization of beneficial microbes, particularly probiotic bacteria such as *Propionibacterium freudenreichii* and *Enterococcus faecium*, with an emphasis on their roles in promoting host health. The lab investigates the mechanisms underlying probiotic-mediated benefits, including lifespan extension in model organisms like *C. elegans*, modulation of intestinal mucus production for inflammatory bowel disease management, and enhancement of osteoblast differentiation for bone health. Using both in vitro and in vivo models, the lab explores microbial metabolites, enzyme activities, and host-microbe interactions to uncover novel therapeutic applications. Their work bridges microbiology, host physiology, and translational medicine, aiming to develop next-generation probiotics for chronic disease prevention and healthy aging.
Figures are computed from collected data and may differ slightly.
Dairy Propionibacterium freudenreichii is a candidate non-lactic acid probiotic. However, little information is available on the effect of P. freudenreichii on lifespan extension in humans. The aim of this study was to evaluate the effects of P. freudenreichii on lifespan extension and to elucidate the mechanism of P. freudenreichii-dependent lifespan extension in Caenorhabditis elegans. The results showed that P. freudenreichii significantly (p < 0.05) extended the lifespan of C. elegans compar
An intact mucus layer is important in managing inflammatory bowel disease (IBD). Dairy Propionibacterium freudenreichii has probiotic potential, produces propionic acid and is known to promote health. The aim of this study was to evaluate the effects of P. freudenreichii on the improvement of colitis. LS 174T goblet cells and a dextran sodium sulfate (DSS)-induced colitis rat model were used to investigate the P. freudenreichii-induced stimulation of mucin production in vitro and in vivo, respec
We have found that Pseudomonas putida ATCC 17642 cells grown in a medium containing D-threonine as the sole nitrogen source produce an enzyme that catalyzes epimerization of threonine. Proton nuclear magnetic resonance analysis of the enzyme reaction in deuterium oxide clearly showed epimerization from L- to D-allo-threonine and also from D- to L-allo-threonine. This is the first example of an enzyme that was clearly shown to epimerize threonine. The enzyme has been purified to homogeneity, whic
Resveratrol (RES) has been studied for its effects on the lifespan extension of Caenorhabditis elegans, but controversy still remains on its mechanism related with SIR-2. In this study, longevity assay was performed to confirm SIR-2-dependent lifespan extension of C. elgeans with RES and oxyresveratrol (OXY), an isomer of hydroxylated RES using loss-of-function mutants of C. elegans including sir-2.1 mutant. The results showed that OXY and RES significantly (P < 0.05) extended the lifespan of C.
Probiotics, including <i>Enterococcus faecium</i>, confer a health benefit on the host. An <i>Enterococcus</i> strain was isolated from healthy chicken cecum, identified as <i>E. faecium</i> by 16S rDNA gene sequence analysis, and designated as <i>E. faecium</i> L11. To evaluate the potential of <i>E. faecium</i> L11 as a probiotic, the gastrointestinal tolerance, immunomodulatory activity, and lifespan extension properties of the strain were assayed. <i>E. faecium</i> L11 showed >66% and >62% s
Osteoblast differentiation is important for the development of bone and the maintenance of bone density. <i>Propionibacterium freudenreichii</i> is a probiotic with an anti-inflammatory property. The aim of this study was to investigate the enhancement effect of <i>P. freudenreichii</i> MJ2 (MJ2) isolated from raw milk on osteoblast differentiation, mineralization, and its signaling pathway. For in vitro and in vivo experiments, human fetal osteoblastic cell line hFOB 1.19 and an ovariectomized
In conclusion, OE could be considered as a reliable and safe herbal medicine or functional food since no toxicity was found under the conditions of this study.
Resveratrol (RSV), a phytoalexin found in grapes and other plants, is known to have antibacterial effects against Escherichia coli. In this study, we aimed to identify the target gene(s) for the antibacterial activity of RSV in E. coli. Using a DNA microarray, we found that exposure to RSV led to changes in the expression levels of iron metabolism genes, and those involved in drug response and respiration. Thus, we measured the antibacterial activity of RSV against 14 E. coli mutants with deleti
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