• Journal of Microbiology and Biotechnology
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• 제34권6호
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• pp.1328-1339
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• 2024

Cadmium (Cd) is a prevalent environmental contaminant that poses a potential hazard to the health of both humans and animals. In this study, biosynthesized selenium-enriched Lactobacillus plantarum and selenium nanoparticles (SeNPs) were developed and evaluated for their protective effects against Cd-induced hepatic injury in mice through oral administration for 4 weeks. Cadmium exposure resulted in severe impairment of liver function, as evidenced by increased levels of serum markers of liver injury and, oxidative stress and significant damage to liver tissue, and a notable decrease in the diversity of the intestinal microbiota. Oral administration of Se-enriched L. plantarum (LS) reduced cadmium accumulation in the liver by 49.5% and, restored other cadmium-induced damage markers to normal levels. A comparison of the effects with those of L. plantarum (L) and SeNPs isolated from LS revealed that LS could more effectively alleviate hepatic oxidative stress and reduce the intrahepatic inflammatory responses of the liver, further protecting against cadmium-induced liver injury. These findings suggest that the development of LS may be effective at protecting the liver and intestinal tract from cadmium-induced damage.

• Journal of Microbiology and Biotechnology
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• 제33권8호
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• pp.1057-1065
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• 2023

Inflammatory bowel disease (IBD), a chronic inflammatory disease, results from dysregulation of the immune responses. Some lactic acid bacteria (LAB), including Lactobacillus, alleviate IBD through immunomodulation. In this study, the anti-colitis effect of LAB isolated from human breast milk was investigated in a mouse model induced acute colitis with 2,4,6-trinitrobenzene sulfonic acid (TNBS). TNBS remarkably increased weight loss, colon shortening, and colonic mucosal proliferation, as well as the expression levels of inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-1β. Oral administration of LAB isolated from human breast milk resulted in a reduction in TNBS-induced colon shortening, as well as induced cyclooxygenase (COX)-2, nitric oxide synthase (iNOS), nuclear factor-kappa B (NF-κB). In addition, LAB suppressed inflammatory cytokines such as TNF-α, IL-6, and IL-1β, and thus showed an effect of suppressing the level of inflammation induced by TNBS. Furthermore, LAB alleviated gut microbiota dysbiosis, and inhibited intestinal permeability by increasing the expression of intestinal tight junction protein including ZO-1. Collectively, these results suggest that LAB isolated from human breast milk can be used as a functional food for colitis treatment by regulating NF-κB signaling, gut microbiota and increasing expression of intestinal tight junction protein.

• Journal of Microbiology and Biotechnology
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• 제28권9호
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• pp.1443-1446
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• 2018

In the present study, we examined whether Lactobacillus johnsonii CJLJ103 (LJ) could alleviate cholinergic memory impairment in mice. Oral administration of LJ alleviated scopolamine-induced memory impairment in passive avoidance and Y-maze tasks. Furthermore, LJ treatment increased scopolamine-suppressed BDNF expression and CREB phosphorylation in the hippocampi of the brain, as well as suppressed $TNF-{\alpha}$ expression and $NF-{\kappa}B$ activation. LJ also increased BDNF expression in corticosterone-stimulated SH-SY5Y cells and inhibited $NF-{\kappa}B$ activation in LPS-stimulated microglial BV2 cells. However, LJ did not inhibit acetylcholinesterase activity. These findings suggest that LJ, a member of human gut microbiota, may mitigate cholinergic memory impairment by increasing BDNF expression and inhibiting $NF-{\kappa}B$ activation.

• Journal of Microbiology and Biotechnology
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• 제26권12호
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• pp.2141-2147
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• 2016

As one of the most complex human-associated microbial habitats, the oral cavity harbors hundreds of bacteria. Halitosis is a prevalent oral condition that is typically caused by bacteria. The aim of this study was to analyze the microbial communities and predict functional profiles in supragingival plaque from healthy individuals and those with halitosis. Ten preschool children were enrolled in this study; five with halitosis and five without. Supragingival plaque was isolated from each participant and 16S rRNA gene pyrosequencing was used to identify the microbes present. Samples were primarily composed of Actinobacteria, Bacteroidetes, Proteobacteria, Firmicutes, Fusobacteria, and Candidate phylum TM7. The ${\alpha}$ and ${\beta}$ diversity indices did not differ between healthy and halitosis subjects. Fifteen operational taxonomic units (OTUs) were identified with significantly different relative abundances between healthy and halitosis plaques, and included the phylotypes of Prevotella sp., Leptotrichia sp., Actinomyces sp., Porphyromonas sp., Selenomonas sp., Selenomonas noxia, and Capnocytophaga ochracea. We suggest that these OTUs are candidate halitosis-associated pathogens. Functional profiles were predicted using PICRUSt, and nine level-3 KEGG Orthology groups were significantly different. Hub modules of co-occurrence networks implied that microbes in halitosis dental plaque were more highly conserved than microbes of healthy individuals' plaque. Collectively, our data provide a background for the oral microbiota associated with halitosis from supragingival plaque, and help explain the etiology of halitosis.

• Journal of Microbiology and Biotechnology
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• 제29권11호
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• pp.1693-1706
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• 2019

Atopic dermatitis (AD) is a chronic inflammatory skin disease of mainly infants and children. Currently, the development of safe and effective treatments for AD is urgently required. The present study was conducted to investigate the immunomodulatory effects of yeast-extracted β-1,3/1,6-glucan and/or Lactobacillus plantarum (L. plantarum) LM1004 against AD-like symptoms. To purpose, β-1,3/1,6-glucan and/or L. plantarum LM1004 were orally administered to AD-induced animal models of rat (histamine-induced vasodilation) and mouse (pruritus and contact dermatitis) exhibiting different symptoms of AD. We then investigated the treatment effects on AD-like symptoms, gene expression of immune-related factors, and gut microbiomes. Oral administration of β-1,3/1,6-glucan (0.01 g/kg initial body weight) and/or 2 × 10¹² cells/g L. plantarum LM1004 (0.01 g/kg initial body weight) to AD-induced animal models showed significantly reduced vasodilation in the rat model, and pruritus, edema, and serum histamine in the mouse models (p < 0.05). Interestingly, β-1,3/1,6-glucan and/or L. plantarum LM1004 significantly decreased the mRNA levels of Th2 and Th17 cell transcription factors, while the transcription factors of Th1 and Treg cells, galactin-9, filaggrin increased, which are indicative of enhanced immunomodulation (p < 0.05). Moreover, in rats with no AD induction, the same treatments significantly increased the relative abundance of phylum Bacteroidetes and the genus Bacteroides. Furthermore, bacterial taxa associated with butyrate production such as, Lachnospiraceae and Ruminococcaceae at family, and Roseburia at genus level were increased in the treated groups. These findings suggest that the dietary supplementation of β-1,3/1,6-glucan and/or L. plantarum LM1004 has a great potential for treatment of AD as well as obesity in humans through mechanisms that might involve modulation of host immune systems and gut microbiota.

• Journal of Periodontal and Implant Science
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• 제53권3호
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• pp.233-244
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• 2023

Purpose: An implant-supported prosthesis consists of an implant fixture, an abutment, an internal screw that connects the abutment to the implant fixture, and the upper prosthesis. Numerous studies have investigated the microorganisms present on the implant surface, surrounding tissues, and the subgingival microflora associated with peri-implantitis. However, there is limited information regarding the microbiome within the internal screw space. In this study, microbial samples were collected from the supragingival surfaces of natural teeth, the peri-implant sulcus, and the implant-abutment screw hole, in order to characterize the microbiome of the internal screw space in healthy subjects. Methods: Samples were obtained from the supragingival region of natural teeth, the peri-implant sulcus, and the implant screw hole in 20 healthy subjects. DNA was extracted, and the V3-V4 region of the 16S ribosomal RNA was sequenced for microbiome analysis. Alpha diversity, beta diversity, linear discriminant analysis effect size (LEfSe), and network analysis were employed to compare the characteristics of the microbiomes. Results: We observed significant differences in beta diversity among the samples. Upon analyzing the significant taxa using LEfSe, the microbial composition of the implant-abutment screw hole's microbiome was found to be similar to that of the other sampling sites' microbiomes. Moreover, the microbiome network analysis revealed a unique network complexity in samples obtained from the implant screw hole compared to those from the other sampling sites. Conclusions: The bacterial composition of the biofilm collected from the implant-abutment screw hole exhibited significant differences compared to the supra-structure of the implant. Therefore, long-term monitoring and management of not only the peri-implant tissue but also the implant screw are necessary.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제13권4호
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• pp.405-411
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• 1991

To determine the sterility of the prepared allogeneic bone of the human, culture of the allografts prior to implantation was performed on fresh-frozen and freeze-dried bone. Before the use of allografts to the patients, it must be confirmed about the sterility, cellular cytotoxicity, immune reaction, and osteoinductive potential as a biomaterials. Oral and maxillofacial surgeons demand for allograft bone will be increased in the future. Wonkwang Bone Bank attempted to meet this demand, has performed series of experimental study on the allograft bone of the Koreans to evaluate the physical and chemical suitability of the bone since the surgeons applications will have broadened from benign cystic lesions to fracture malunions and non-unions, large segmental defects, and whole-bone allorgrafts after tumor surgery. The results obtained were as follows: 1. Freeze-drying(FD) only shoed some bactericidal effects of the normal and osteo bone but in cases of performing EO gas sterilization, the FD effects was not clear. 2. The fact that FD has little effect than the EO gas sterilization on normal bone postulated that the presence of microbiota may be due to an operation and bone processing procedure. 3. FD and EO gas sterilization had a remarkable effect on the osteo bone. 4. The sterilization effect were EO gas, Freeze-drying, Fresh-Frozen with descending order. But all sterilization method were not complete to preserve and implant allograft bone. We are now performing further continuous study on the radiation and chemical sterilization procedure to make safe and complete allograft bone.

• 치위생과학회지
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• 제23권1호
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• pp.13-19
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• 2023

Background: Periodontitis is a chronic inflammatory condition associated with dysbiosis of the oral microbiota. The aim of the present clinical study was to explore the adjunctive effect of ozonized water irrigation in the circuits of ultrasonic scalers for the full-mouth decontamination of patients with periodontitis Stage I or II. Methods: The study was a randomized, single-blinded, parallel-group clinical trial. The test group (n=25) was treated with ultrasonic scalers irrigated with ozonized water, whereas the control group (n=25) received normal tap water irrigation within the ultrasonic scalers used during the professional mechanical debridement. Full mouth plaque score, bleeding score, probing pocket depth, and the gingival index were evaluated at baseline, two, and 4 weeks after treatment. The pain perceived and dental anxiety were also assessed after treatment by means of the visual analog scale (VAS). Results: All periodontal parameters resulted in significant improvement for both study groups. The effect of the treatment group on the gingival index was significant, in particular, patients in the test group experienced a greater reduction in this score. No significant differences could be observed with regards to the average probing depth, full mouth plaque index and bleeding score. Patients treated with ozonized water running in the circuits of ultrasonic scalers displayed also lower scores for pain and dental anxiety. Conclusion: The present study showed a significant clinical effect on gingival inflammation attributable to adjunctive ozone irrigation during nonsurgical periodontal therapy. Further studies, including patients with severe periodontitis and greater sample sizes, are recommended to test the clinical effect of ozonized water in the circuits of ultrasonic scalers.

• Journal of Microbiology and Biotechnology
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• 제28권1호
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• pp.65-76
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• 2018

Although there has been a steady increase in the prevalence of food allergies worldwide in recent decades, no effective therapeutic strategies have been developed. Modulation of the gut microbiota composition and/or function through probiotics has been highlighted as a promising target for protection against food allergies. In this study, we aimed to investigate the allergy-reducing effects of a probiotic mixture (P5: Lactococcus lactis KF140, Pediococcus pentosaceus KF159, Lactobacillus pentosus KF340, Lactobacillus paracasei 698, and Bacillus amyloliquefaciens 26N) in mice with ovalbumin (OVA)-induced food allergy. Administration of P5 significantly suppressed the oral OVA challenge-induced anaphylactic response and rectal temperature decline, and reduced diarrhea symptoms. Moreover, P5 also significantly inhibited the secretion of IgE, Th2 cytokines (interleukin (IL)-4, IL-5, IL-10, and IL-13), and Th17 cytokines (IL-17), which were increased in mice with OVA-induced food allergy, and induced generation of CD4+Foxp3+ regulatory T cells. These results revealed that P5 may have applications as a preventive agent against food allergy.

• 한국치위생학회지
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• 제2권2호
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• pp.201-213
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• 2002

The closely related species Actinobacillus actinomycetemcomitans, Hemophilus aphrophilus and Hemophilus paraphrophilus are common findings in oral microbiota. The aims of this study were to compare the distribution of three species in healthy subjects and periodontitis patients using PCR for 16s rRNA gene. The DNA was extracted from the subgingival plaque and saliva in 122 subjects for restriction enzyme analysis with Hinf I and Hha I. In case of periodontally healthy person, A. actinomycetemcomitans was predominant than H. paraphrophilus in saliva sample, but H. paraphrophilus was predominant than A. actinomycetemcomitans in subgingival plaque sample. On the contrary, in case of periodontitis patients, H. paraphrophilus was predominant than A. actinomycetemcomitans in saliva sample, but A. actinomycetemcomitans was predominant than H. paraphrophilus in subgingival plaque sample. In addition, the fact was confirmed that the distribution of A. actinomycetemcomitns of women periodontitis patients was somewhat higher than men periodontitis patients in saliva and subgingival plaque samples. We convinced that the PCR method for 16s rRNA gene was important for screening and monitoring of periodontal disease.