• Journal of Microbiology and Biotechnology
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• 제34권9호
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• pp.1739-1747
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• 2024

Alzheimer's disease (AD) is a progressive neurological disorder that represents a major cause of dementia worldwide. Its pathogenesis involves multiple pathways, including the amyloid cascade, tau protein, oxidative stress, and metal ion dysregulation. Recent studies have suggested a critical link between changes in gut microbial diversity and the disruption of the gut-brain axis in AD. Previous studies primarily explored the potential benefits of probiotics and prebiotics in managing AD. However, studies have yet to fully describe a novel promising approach involving the use of synbiotics, which include a combination of active probiotics and new-generation prebiotics. Synbiotics show potential for mitigating the onset and progression of AD, thereby offering a holistic approach to address the multifaceted nature of AD. This review article primarily aims to gain further insights into the mechanisms of AD, specifically the intricate interaction between gut bacteria and the brain via the gut-brain axis. By understanding this relationship, we can identify potential targets for intervention and therapeutic strategies to combat AD effectively. This review also discusses substantial evidence supporting the role of synbiotics as a promising AD treatment that surpasses traditional probiotic or prebiotic interventions. We find that synbiotics may be used not only to address cognitive decline but also to reduce AD-related psychological burden, thus enhancing the overall quality of life of patients with AD.

• 한국미생물·생명공학회지
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• 제31권3호
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• pp.297-300
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• 2003

In order to select probiotics with a high survival rate in gut and the growth inhibition of virulent pathogens to human beings or animals, we have screened lactic acid bacteria and yeasts from Jeot-gal to assess resistance against the artificial gastric acid and bile juice. Lactic acid bacteria and yeasts isolated were incubated for 24 h in artificial bile juice after incubation for 2 h in artificial gastric acid. Especially, strain HW 161 and strain NK 181 showed the higher survival for 2 h incubation in artificial gastric acid. All of 3 strains of lactic acid bacteria and 2 strains of yeast were showed higher growth rate than the control in artificial bile. The antimicrobial activity of lactic acid bacteria and yeasts was also investigated to prove efficacy as probiotic organisms. Lactic acid bacteria were shown the inhibition of Gram positive and negative bacteria, but yeasts narrow inhibition.

• Asian-Australasian Journal of Animal Sciences
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• 제27권6호
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• pp.898-906
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• 2014

The objective of this study was to investigate differences in the faecal microbial composition among Lantang, Bama, Erhualian, Meishan, Xiaomeishan, Duroc, Landrace, and Yorkshire sows and to explore the possible link of the pig breed with the gut microbial community. Among the sows, the Meishan, Landrace, Duroc, and Yorkshire sows were from the same breeding farm with the same feed. Fresh faeces were collected from three sows of each purebred breed for microbiota analysis and volatile fatty acid (VFA) determination. Denaturing gradient gel electrophoresis (DGGE) analysis revealed that samples from Bama, Erhualian, and Xiaomeishan sows, which from different farms, were generally grouped in one cluster, with similarity higher than 67.2%, and those from Duroc, Landrace, and Yorkshire sows were grouped in another cluster. Principal component analysis of the DGGE profile showed that samples from the foreign breeds and the samples from the Chinese indigenous breeds were scattered in two different groups, irrespective of the farm origin. Faecal VFA concentrations were significantly affected by the pig breed. The proportion of acetate was higher in the Bama sows than in the other breeds. The real-time PCR analysis showed that 16S rRNA gene copies of total bacteria, Firmicutes and Bacteroidetes were significantly higher in the Bama sows compared to Xiaomeishan and Duroc sows. Both Meishan and Erhualian sows had higher numbers of total bacteria, Firmicutes, Bacteroidetes and sulphate-reducing bacteria as compared to Duroc sows. The results suggest that the pig breed affects the composition of gut microbiota. The microbial composition is different with different breeds, especially between overseas breeds (lean type) and Chinese breeds (relatively obese type).

• 한국미생물·생명공학회지
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• 제38권2호
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• pp.117-123
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• 2010

BT toxin is produced by a soil bacterium Bacillus thuringiensis and has long been used as a biological insecticide without any competition. Recently, Photorhabdus, a symbiotic bacterium from entomopathogenic nematodes, family Heterorhabditae, has been researched and discussed as alternatives to B. thuringiensis. Photorhabdus, which lives in the gut of entomopathogenic nematodes, is a highly virulent pathogen of a wide range of insect larvae. When an insect is infected by the nematodes, the bacteria are released into the cadaver, and produce a number of insecticidal toxins. The biological role of the different Photorhabdus toxins in the infection process is still unclear. Photorhabdus toxin complex (Tc) is highly secreted gut-active toxin and has been characterized as a potent three-component (A, B and C) insecticidal protein complex. These components are necessary for full oral activity against insect larvae. The Photorhabdus PirAB binary toxins exhibit a potent injectable activity for Galleria mellonella larvae, and have oral toxicity against mosquitoes and caterpillar pest Plutella xylostella. Other toxin, 'makes caterpillars floppy' (Mcf) showed injectable activity on caterpillars. Recombinant Mcf triggers apoptosis in both insect hemocytes and the midgut epithelium and carries a BH3 domain. In this review, the relationship between the Photorhabdus and the nematode is discussed and recent important insecticidal toxins from Photorhabdus are described.

• Asian-Australasian Journal of Animal Sciences
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• 제29권1호
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• pp.16-22
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• 2016

The intestinal environment plays a critical role in maintaining swine health. Many factors such as diet, microbiota, and host intestinal immune response influence the intestinal environment. Intestinal alkaline phosphatase (IAP) is an important apical brush border enzyme that is influenced by these factors. IAP dephosphorylates bacterial lipopolysaccharides (LPS), unmethylated cytosine-guanosine dinucleotides, and flagellin, reducing bacterial toxicity and consequently regulating toll-like receptors (TLRs) activation and inflammation. It also desphosphorylates extracellular nucleotides such as uridine diphosphate and adenosine triphosphate, consequently reducing inflammation, modulating, and preserving the homeostasis of the intestinal microbiota. The apical localization of IAP on the epithelial surface reveals its role on LPS (from luminal bacteria) detoxification. As the expression of IAP is reported to be downregulated in piglets at weaning, LPS from commensal and pathogenic gram-negative bacteria could increase inflammatory processes by TLR-4 activation, increasing diarrhea events during this phase. Although some studies had reported potential IAP roles to promote gut health, investigations about exogenous IAP effects or feed additives modulating IAP expression and activity yet are necessary. However, we discussed in this paper that the critical assessment reported can suggest that exogenous IAP or feed additives that could increase its expression could show beneficial effects to reduce diarrhea events during the post weaning phase. Therefore, the main goals of this review are to discuss IAP's role in intestinal inflammatory processes and present feed additives used as growth promoters that may modulate IAP expression and activity to promote gut health in piglets.

• 문화기술의 융합
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• 제5권4호
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• pp.421-429
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• 2019

본 연구는 한국산 초임계 열처리된 무 복합 추출물을 이용하여 장내세균의 생육, 특히 식중독 및 위염, 장염 등 감염성 유해균과 정장효과를 나타내는 유익한 세균군의 생육에 미치는 영향을 알아보고자 하였다. 흰쥐를 3개 시험구 즉 정상대조군, Loperamide 투여군, 초임계 열처리된 무 복합추출물(HRE) 투여군 등으로 나누어 동물실험을 수행하면서 장내 유익한 세균의 생육에는 아무런 영향을 주지 않으면서 유해균의 생육을 저해함으로써 장기능 개선 및 세균성 장질환에 효과적이고 안전한 건강기능식품 조성물로도 유용하게 사용할 수 있다는 결과를 얻었다. 특히 무는 오랫동안 복용 시에도 전혀 부작용을 나타내지 않는 안전한 식품으로 장기간 꾸준히 복용하는 것에 의해 장내 세균총 및 세균성 장질환에 효과를 얻을 수 있다는 결론을 얻을 수 있었다.

• Journal of Applied Biological Chemistry
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• 제64권1호
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• pp.75-81
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• 2021

최근의 장내 미생물 연구에 따르면 우리의 건강에 대한 장내 미생물의 중요한 역할이 밝혀졌다. 이에 매년 다양한 건강 기능 식품이 개발되고 있다. 기능성 식품의 개발에는 기능성 식품의 유익한 효과를 확인하기위한 in-vivo 실험이 포함되는 경우가 많다. 그 이유로 기능성 식품이 장내 미생물에 미치는 영향을 조사하기 위해서 동물 실험을 자주 수행하고 있는 실정이다. 식품의 유익한 효과는 장내 미생물 생태가 식품에 의해 이동되어 유익한 박테리아의 증가, 잠재적인 병원성 박테리아의 감소 또는 둘 다에 따라 평가 될 수 있다. 동물 실험은 일반적으로 시간이 많이 걸리고 까다롭기 때문에 본 연구팀은 분변 미생물에 대한 in-vitro 연구로 식이 건강상의 이점을 얼마나 잘 반영하는지 조사했다. 본 연구에서는 두 사람의 배설물을 사용하여 15가지 음식이 장내미생물에 주는 영향을 조사했다. 결과는 식단에 따라 다양한 장내 미생물 이동을 보여 주었으며, 이는 일반적으로 알려진 유익한 식단(즉, 김치, 청국장)이 유산균과 비피도 박테리움을 증가 시켰음을 확인했다. 따라서, 우리는 식이 요법의 유익한 효과를 평가하기 위해 체외 분변 미생물균총 분석을 사용할 수 있다고 제안한다. 또한, 이 방법은 더 나아가 개인 맞춤형 식단을 설정하는 데 도움이 될 수 있다고 사료된다.

• Journal of Microbiology and Biotechnology
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• 제28권6호
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• pp.976-986
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• 2018

Knowledge about the gut bacterial communities associated with insects is essential to understand their roles in the physiology of the host. In the present study, the gut bacterial communities of a laboratory-reared insecticide-susceptible (IS), and a field-collected insecticide-resistant (IR) population of a major rice pest, the brown planthopper Nilaparvata lugens, were evaluated. The deep-sequencing analysis of the V3 hypervariable region of the 16S rRNA gene was performed using Illumina and the sequence data were processed using QIIME. The toxicological bioassays showed that compared with the IS population, IR population exhibited 7.9-, 6.7-, 14.8-, and 18.7-fold resistance to acephate, imidacloprid, thiamethoxam, and buprofezin, respectively. The analysis of the alpha diversity indicated a higher bacterial diversity and richness associated with the IR population. The dominant phylum in the IS population was Proteobacteria (99.86%), whereas the IR population consisted of Firmicutes (46.06%), followed by Bacteroidetes (30.8%) and Proteobacteria (15.49%). Morganella, Weissella, and Enterococcus were among the genera shared between the two populations and might form the core bacteria associated with N. lugens. The taxonomic-to-phenotypic mapping revealed the presence of ammonia oxidizers, nitrogen fixers, sulfur oxidizers and reducers, xylan degraders, and aromatic hydrocarbon degraders in the metagenome of N. lugens. Interestingly, the IR population was found to be enriched with bacteria involved in detoxification functions. The results obtained in this study provide a basis for future studies elucidating the roles of the gut bacteria in the insecticide resistance-associated symbiotic relationship and on the design of novel strategies for the management of N. lugens.

• 한국축산식품학회지
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• 제44권2호
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• pp.299-308
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• 2024

Proteins in whey have prebiotic and antimicrobial properties. Whey protein comprises numerous bioactive proteins and peptides, including glycomacropeptide (GMP), a hydrophilic casein peptide that separates with the whey fraction during cheese making. GMP has traditionally been used as a protein source for individuals with phenylketonuria and also has prebiotic (supporting the growth of Bifidobacterium and lactic acid bacteria) and antimicrobial activities. GMP supplementation may help positively modulate the gut microbiome, help treat dysbiosis-related gastrointestinal disorders and improve overall health in consumers.

• Journal of Microbiology and Biotechnology
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• 제25권5호
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• pp.687-695
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• 2015

Accumulating evidence indicates that lactic acid bacteria could improve host physiology and lipid metabolism. To investigate the effect of the gut microbiota on host lipid metabolism, a hyperlipidemic rat model was established by feeding rats a high-fat diet for 28 days, and the gut microbiota of the rats was analyzed using real-time PCR before and after administration of Lactobacillus rhamnosus hsryfm 1301 and its fermented milk for 28 days. The findings showed that the Lactobacillus spp., Bifidobacterium spp., Bacteroides spp., and Enterococcus spp. content in the hyperlipidemic rats gut was increased significantly (p < 0.05), while the Clostridium leptum and Enterobacter spp. content was decreased significantly after intervening with L. rhamnosus hrsyfm 1301 and its fermented milk for 28 days (p < 0.05). Furthermore, the lipid levels of the serum and the liver were decreased significantly (p < 0.05) and the fecal water content was increased significantly (p < 0.05) in the hyperlipidemic rats after the intervention, and hepatocyte fatty degeneration of liver tissues was also prevented. A positive correlation was observed between the Clostridium leptum content and the level of serum cholesterol, triglycerides, low-density lipoprotein, and high-density lipoprotein, and a negative correlation was observed between the Enterobacter spp. content and the Lactobacillus spp. and Bifidobacterium spp. content in the hyperlipidemic rats gut. These results suggest that the gut microbiota and lipid metabolism of hyperlipidemic rats could be improved by supplementation with L. rhamnosus hsryfm 1301 and its fermented milk.