• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.20 no.3
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• pp.139-146
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• 2017

The number of papers discussing probiotics increases tremendously that limits the possibility for primary care physicians and clinicians to stay updated. Therefore, the aim of this paper will be to summarize available evidence of probiotic use in well-defined clinical indications of importance for pediatricians. Based on currently available evidence certain probiotic strains (Lactobacillus rhamnosus GG [LGG] and Saccharomyces boulardii) have proven effect in the treatment of acute gastroenteritis and prevention of antibiotic associated diarrhea. Furthermore, LGG was proven to be effective in prevention of nosocomial diarrhea and respiratory tract infection in day care centers. In conclusion, not all probiotic strains have same efficacy for all clinical indications, therefore, only strains with proven efficacy and safety should be recommended.

• Journal of Microbiology and Biotechnology
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• v.27 no.11
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• pp.1971-1982
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• 2017

Piliated Lactobacillus rhamnosus (pLR) strains possess higher adherent capacity than non-piliated strains. The objective of this study was to isolate and characterize probiotic pLR strains in human fecal samples. To this end, mouse polyclonal antiserum (anti-SpaA) against the recombinant pilus protein (SpaA) of L. rhamnosus strain GG (LGG) was prepared and tested for its reactivity and specificity. With the anti-SpaA, a method combining the de Man, Rogosa, and Sharpe (MRS) agar plating separation and colony immunoblotting (CIB) was developed to isolate pLR from 124 human fecal samples. The genetic and phenotypic characteristics of the resultant pLR isolates were compared by randomly amplified polymorphic DNA (RAPD) fingerprinting, and examination of adhesion to Caco-2 cells, hydrophobicity, autoaggregation, and in vitro gastrointestinal tolerance. Anti-SpaA specifically reacted with three pLR strains of 25 test strains, as assessed by western blotting, immunofluorescence flow cytometry, and immunoelectron microscopy (IEM) assays. The optimized MRS agar separation plus anti-SpaA-based CIB procedure could quantitatively detect $2.5{\times}10^3CFU/ml$ of pLR colonies spiked in $10^6CFU/ml$ of background bacteria. Eight pLR strains were identified in 124 human fecal samples, and were confirmed by 16S RNA gene sequencing and IEM identification. RAPD fingerprinting of the pLR strains revealed seven different patterns, of which only two isolates from infants showed the same RAPD profiles with LGG. Strain PLR06 was obtained with high adhesion and autoaggregation activities, hydrophobicity, and gastrointestinal tolerance. Anti-SpaA-based CIB is a rapid and inexpensive method for the preliminary screening of novel adherent L. rhamnosus strains for commercial purposes.

• Journal of Microbiology and Biotechnology
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• v.29 no.8
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• pp.1248-1254
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• 2019

Identification of novel probiotic strains is of great interest in the field of functional foods. Specific strains of heat-killed bacteria have been reported to exert immunomodulatory effects. Herein, we investigated the immune-stimulatory function of heat-killed Lactobacillus plantarum KCTC 13314BP (LBP). Treatment with LBP significantly increased the production of $TNF-{\alpha}$ and IL-6 by macrophages. More importantly, LBP was able to enhance the phagocytic activity of macrophages against bacterial particles. Activation of p38, JNK, ERK, $NF-{\kappa}B$, and STAT3 was involved in the immunomodulatory function of LBP. LBP treatment significantly increased production of $TNF-{\alpha}$ by bone marrow-derived macrophages and splenocytes, further confirming the immunostimulatory effect of LBP in primary immune cells. Interestingly, the immunomodulatory effects of LBP were much stronger than those of Lactobacillus rhamnosus GG, a well-known probiotic strain. These results indicate that LBP can be a promising immune-enhancing functional food agent.

• Journal of Microbiology and Biotechnology
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• v.31 no.5
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• pp.726-732
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• 2021

In this study, we evaluated the immune-enhancing activity of kimchi-derived Lactobacillus plantarum 200655 on immune suppression by cyclophosphamide (CP) in ICR mice. Animals were fed distilled water or 1×10⁹ colony-forming unit/kg B.W. 200655 or Lactobacillus rhamnosus GG as a positive control for 14 days. An in vivo model of immunosuppression was induced using CP 150 and 100 mg/kg B.W. at 7 and 10 days, respectively. Body weight, spleen index, spleen weight, and gene expression were measured to estimate the immune-enhancing effects. The dead 200655 (D-200655) group showed an increased spleen weight compared to the sham control (SC) group. Similarly, the spleen index was significantly higher than that in the CP-treated group. The live 200655 (L-200655) group showed an increased mRNA expression of tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6 in splenocytes. Also, the iNOS and COX-2 mRNA expression was upregulated in the L-200655 group compared to the CP-only (SC) group. The phosphorylation of ERK and MAPK was also upmodulated in the L-200655 group. These results indicate that L. plantarum 200655 ameliorated CP-induced immune suppression, suggesting that L. plantarum 200655 may have the potential to enhance the immune system.

• Journal of Microbiology and Biotechnology
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• v.26 no.7
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• pp.1333-1340
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• 2016

The main objective of this study was to investigate whether Lactobacillus rhamnosus GG (LGG) ameliorated the effects of Citrobactor rodentium infection in Toll-like receptor 2 (TLR2) knockout (KO) and TLR4 KO mice, as well as in wild-type C57BL/6 (B6) mice. TLR2 KO, TLR4 KO, and B6 mice were divided into three groups per each strain. Each group had an uninfected control group (n = 5), C. rodentium-infected group (n = 8), and LGG-pretreated C. rodentium-infected group (n = 8). The survival rate of B6 mice infected with C. rodentium was higher when pretreated with LGG. Pretreatment with LGG ameliorated C. rodentium-induced mucosal hyperplasia in B6 and TLR4 KO mice. However, in C-rodentium-infected TLR2 KO mice, mucosal hyperplasia persisted, regardless of pretreatment with LGG. In addition, LGG-pretreated B6 and TLR4 KO mice showed a decrease in spleen weight and downregulation of tumor necrosis factor alpha, interferon gamma, and monocyte chemotactic protein 1 mRNA expression compared with the non-pretreated group. In contrast, such changes were not observed in TLR2 KO mice, regardless of pretreatment with LGG. From the above results, we conclude that pretreatment with LGG ameliorates C. rodentium-induced colitis in B6 and TLR4 KO mice, but not in TLR2 KO mice. Therefore, LGG protects mice from C. rodentium-induced colitis in a TLR2-dependent manner.

• Journal of Dairy Science and Biotechnology
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• v.37 no.4
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• pp.223-236
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• 2019

This study aimed to investigate the physiological characteristics and anti-diabetic effects of Lactobacillus plantarum KI69. The α-amylase and α-glucosidase inhibitory activity of L. plantarum KI69 was 91.17±2.23% and 98.71±4.23%, respectively. The propionic, acetic, and butyric acid contents of the MRS broth inoculated with L. plantarum KI69 were 8.78±1.12 ppm, 1.34±0.07% (w/v), and 0.876±0.003 g/kg, respectively. L. plantarum KI69 showed higher sensitivity to penicillin-G, oxacillin, and chloramphenicol among 16 different antibiotics and showed the highest resistance to ampicillin and vancomycin. The strain showed higher β-galactosidase, β-glucosidase, and N-acetyl-β-glucosaminidase activities than other enzymes. Additionally, it did not produce carcinogenic enzymes, such as β-glucuronidase. The survival rate of L. plantarum KI69 in 0.3% bile was 96.42%. Moreover, the strain showed a 91.45% survival rate at pH 2.0. It was resistant to Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus with the rates of 15.44%, 50.79%, 58.62%, and 37.85%, respectively. L. plantarum (25.85%) showed higher adhesion ability than the positive control L. rhamnosus GG (20.87%). These results demonstrate that L. plantarum KI69 has a probiotic potential with anti-diabetic effects.

• Journal of Dairy Science and Biotechnology
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• v.38 no.4
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• pp.207-221
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• 2020

This study aimed to investigate the physiological characteristics and anti-obesity effects of milk fermented by L. plantarum KI134. The lipase, α-amylase, and α-glucosidase inhibitory activities of milk fermented by L. plantarum KI134 was 94.57±1.25%, 9.44±2.85%, and 2.74±1.24% (10 fold dilution), respectively. L. plantarum KI134 showed higher sensitivity to clindamycin and erythromycin in comparison to sixteen different antibiotics. It demonstrated the highest resistance toward ampicillin and vancomycin. The strain showed higher β-galactosidase, leucine arylamidase, valine arylamidase, acid phosphatase, β-glucosidase, and N-acetyl-β-glucosaminidase activities compared to other enzymes. It also did not produce carcinogenic enzymes, such as β-glucuronidase. The survival rate of L. plantarum KI134 in 0.3% bile was 96.90%. Moreover, the strain showed a 91.45% survival rate at a pH of 2.0. L. plantarum KI134 has resistance to Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus at the rates of 70.00%, 68.18%, 59.05%, and 40.63%, respectively. L. plantarum KI134 (23.01%) showed higher adhesion ability than the positive control (16.32%) L. rhamnosus GG. These results demonstrated that milk fermented by L. plantarum KI134 demonstrated an anti-obesity effect under in vitro conditions, with confirmed potential as a probiotic.

• Korean Journal of Food Science and Technology
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• v.53 no.2
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• pp.204-212
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• 2021

Resazurin, an oxidized blue dye, is reduced to resorufin, showing a peak absorbance change and emitting fluorescence due to the metabolic activity of living cells. In this study, the growth of Lactobacillus rhamnosus GG (LGG) and the redox potential of living probiotic bacteria were evaluated based on changes in the absorbance or fluorescence of resazurin. Fluorescence analysis is a more accurate and sensitive method for quantifying viable LGG than the colorimetric absorbance measurement of resazurin change. Fluorescence measurement could detect LGG of 6.5-9.5 log CFU/mL within 30 min with R2=0.99. No significant effect of further reduction of resorufin to dihydroresorufin by LGG was observed. Various probiotics showed different resazurin-reducing activities, and L. kimchicus had the highest reducing activity among the six probiotics tested. These findings suggests that fluorescence measurement in a resazurin-based assay is useful for analyzing bacterial growth and the redox potential of living probiotics.

• Food Science and Industry
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• v.44 no.1
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• pp.59-62
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• 2011

전세계적으로 감염성 질환은 주요한 건강 문제이다. 장내 미생물 균총은 해로운 미생물로부터 숙주를 보호할 뿐 아니라 면역계에 있어서 매우 중요한 역할을 한다. 이점이 바로 프로바이오틱스 즉, 건강에 도움을 주며 살아있는 미생물로 정의되는 기본 개념을 탄생시켰다. Lactobacillus rhamnosus GG(이하 LGG) 균은 세계적으로 가장 많이 연구된 프로바이오틱스 균종 중 하나로서, 확인된 효능의 대부분은 주로 위장관 질환에 관한 것이다. 몇몇 연구를 통해 급성 수양성 설사의 치료, 항생제 관련 증상의 예방, 그리고 여행자 설사에 대한 LGG균의 효과가 밝혀졌다. LGG균은 소아에서 호흡기 감염의 발생을 줄이거나 그 합병증을 감소시키는 것으로 보인다. 많은 연구를 통해 LGG 균, LC705, 그리고 프로피오니박테리움 PJS균을 모두 포함한 복합 유산균 제제인 $LGG^{(R)}$ Extra가 위장관 불편감을 줄이고 삶의 질을 향상시키는 것으로 나타났다. 따라서 LGG균의 사용은 감염성 질병의 관리와 위장관 건강을 얻는데 있어 안전하고 쉬운 방법이라 하겠다.

• Food Science and Industry
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• v.44 no.1
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• pp.63-68
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• 2011

Lactobacillus rhamnosus GG(ATCC 53013) 유산균은 현재 가장 많은 연구가 진행되고 있는 프로바이오틱 유산균들 중 하나이다. 이 유산균은 내산성, 내담즙성, 특유의 콜로니 모양, 장 정착성, 병원성 세균에 대한 경쟁적 저해작용 등의 선택기준을 통하여 분리되었고, 그 특성이 밝혀져 있다. 프로바이오틱 유산균의 선택기준이 진보하고 있지만, LGG 유산균은 아직도 매우 우수한 프로바이오틱 유산균이다. LGG 유산균은 그 유전적인 특성뿐만 아니라 설사예방, 아토피성 습진, 호흡기 감염에 대한 우수성이 임상시험을 통하여 입증되었다. 최근에는 임산부와 영아의 과체중에 대한 개선효과가 임상시험을 통해 증명되어 있다. 향후에는 특정 유산균 단독이나 과학적인 방법으로 선택된 프로바이오틱 유산균의 조합에 의한 유익성을 중심으로 복합 균주의 효과에 대한 새로운 증명이 기본적인 임상시험을 형성하게 될 것이다.