• 한국미생물·생명공학회지
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• 제33권3호
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• pp.159-168
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• 2005

인간의 장(腸)은 태어날 때만 해도 무균 상태이지만 태어나면서 산모나 주위 환경에 의해 미생물이 형성되기 시작한다. 미생물은 숙주 안에서 면역, 영양학적, 생리학적, 보호과정 등의 특징을 유발시키며, 밀접한 상호작용을 한다[6,24, 35]. 많은 연구를 통해 장내 미생물이 우리에게 주는 이로운 점들이 밝혀 지긴 했지만, 우리가 목표로 하는 장내 미생물이 숙주의 장내, 건강 상태를 조절하는 메커니즘은 아직 뚜렷하게 밝혀 지지 않고 있다. 즉, 숙주(인간)의 건강의 상태를 결정지어 주는 장내미생물 biomarker의 확립이 아직 불분명한 상태이다. 장내미생물의 방대한 다양성으로 인하여, 이를 연구하기 위한 분자 생태학 기술의 올바른 접목과 더 나은 방향으로의 기술 발전이 필요하다. 앞으로 더 나은 기술 개발을 통해, 신생아 장내의 초기에 형성되는 미생물을 검출하고, 여러 외부 요인에 따라 어떻게 연속되어 가면서 어떠한 역할을 하는지를 밝힐 수 있다면, 질병 치료뿐 아니라 예방도 가능해 질 것이다.

• 한국미생물·생명공학회지
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• 제27권2호
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• pp.102-106
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• 1999

To investigate the effect of wormwood extract on intestinal Microorganisms of human, we examined the changes of the intestinal microflora of 6 volunteers for 13 days. Numbers of total anaerobes in feces of 6 volunteers showed 1010cfu/g before and after intake of wormwood extract. In case of beneficial Microorganisms, wormwood extract did not have an effect on the growth of bifidobacteria and Lactobacillus spp. On the other hand, the growth of C. perfringens and E. coli, the harmful Microorganisms of human intestines, was inhibited by the wormwood extract.

• Journal of Microbiology and Biotechnology
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• 제14권2호
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• pp.350-355
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• 2004

Sulforhodamine B (SRB) assay is a rapid, sensitive, and inexpensive method for measuring cell proliferation and chemosensitivity. However, the lactate dehydrogenase (LDH) release assay is generally used to measure cytototoxicity of infectious microorganisms against host cells. In this study, we investigated the possibility of applying the SRB assay to determine cytotoxicity for infectious microorganisms, and compared the results with those obtained by the LDH release assay. We used Vibrio vulnificus as a model of infectious microorganisms. The SRB assay showed that V vulnificus strongly induced cytotoxic activity against human intestinal cells, Caco-2 and INT-407 cells. The degree of cytotoxicity closely correlated with infection time and number ratios of V. vulnificus to intestinal cells (MOI, multiplicity of infection). Furthermore, cytotoxicity values obtained by SRB assay correlated well with results obtained by the LDH release assay, and both assays gave a linear response with respect to MOI Heat-inactivation of V. vulnificus for 35 min at $60^{\circ}C$ did not induce cytotoxic activity, indicating that viability of V. vulnificus is crucial for cytotoxic activity against intestinal cells. Although both assays are suitable as cytotoxicity endpoints, the SRB assay is recommended for measuring cytotoxicity of infectious microorganisms against host cells because of its significantly lower cost and more stable endpoint than the LDH release assay.

• 한국미생물·생명공학회지
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• 제23권6호
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• pp.633-640
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• 1995

As a result of screening the medicinal herbs which selectively control human intestinal microflora, water extract of Akebia quinata Decaisne was proved to have a strong inhibitory activity against the growth of Clostridium pefringens, a major harmful intestinal bacterium. The anti-bacte-rial activity was stable under the thermal treatment at 100$\circ$C for 120 min and in a range of pH 1 to 11. In addition, the water extract of Akebia quinata Decaisne showed the antibacterial activities against five different strains of Clostridia including C. perfringens. On the contrary, the extract did not inhibit the growths of Bifidobacterium, Lactobacillus, Escherichia coli, Enterococcus faecalis. The extract, however, suppressed markedly the growth of Bacteroides fragilis and Staphylococcus aureus in vitro. Alike in the mixed culture inoculated with human feces as starter, in vivo tests using rats showed that the extract tends to increase the numbers of Bifidobacteria and Lactobacilli in the intestinal microflora of rats, whereas those of Clostridia were attenuated.

• 한국식품영양학회지
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• 제24권4호
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• pp.817-832
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• 2011

불가리아 사람들이 장수하는 것은 요구르트를 많이 섭취하여 유산균이 장내의 독소 생성 세균을 억제하기 때문이라고 한다. 젊을 때는 사람의 장 내용물 1 g당 100억 마리 이상의 $Bifidobacterium$이 살지만 노쇠하거나 병들면서 줄어들고 $Clostridium$ 등의 유해균이 많아진다. 그래서 인공적으로 장내의 비피도박테리움을 증가시키면 유해세균이 억제되어 건강하고 장수한다고 한다. 이를 위하여 섭취하는 미생물을 probiotic 미생물이라고 하며, 주로 유산균이 사용된다. 프로바이오틱 미생물은 항생제와 같이 유해균을 죽이는 것이 아니라 유해균과 공생하면서 유해균을 억제하여 건강을 증진, 즉 숙주(사람)를 증생(增生)시킨다. 그래서 유산균을 주체로 하는 프로바이오틱 미생물과 그 제품은 변비, 설사, 장염, 혈중 콜레스테롤, 암 등을 예방 내지 치료하고 정장(淨腸) 작용으로 건강을 향상시킨다고 하여 시장이 계속 확대되고 있다. 그러나 국내 프로바이오틱스 제품은 종균을 대부분(90%) 수입하여 사용하므로 한국인의 체질에 적합하지 않을 가능성이 있다. 그래서 E사는 자체 개발한 미생물로 제품을 생산하고 있다. 본 논문에서는 유산균을 주체로 하는 프로바이오틱 미생물과 제품의 효과와 특성, 종류, 시장 등 전반적인 면을 살펴 보았다.

• 한국식품영양과학회지
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• 제31권6호
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• pp.1112-1118
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• 2002

민들레의 추출물을 급여한 흰쥐에게 streptozotocin으로 당뇨를 유발하여 장내 미생물 균총에 미치는 영향을 구명하기 위하여 Wistar계의 이유한 웅성 흰쥐 64마리를 난괴법으로 8군으로 나누어 streptozotocin(55 mg/kg BW)과 식이 kg당 11.45g의 민들레가 함유되도록 부위와 분획별로 나누어 식이에 첨가하여 50일간 사육하였다. 당뇨-대조군의 총혐기성균은 14일간 증가하다가 당뇨로 인하여 감소를 나타내었으며 잎 추출물 급여시 50일에는 당뇨-대조군에 비하여 증가되었다. 뿌리에틸아세테이트 추출물 급여군은 당뇨-대조군에 비하여 총혐 기성균수가 많은 것으로 나타났다. 민들레의 잎과 뿌리의 추출물 급여초기인 14일의 총호기성균은 당뇨-대조군에 비하여 높았으나 35일에는 당뇨-대조군에 비하여 낮은 것으로 나타났으며 50일에 총호기성균수의 변화결과는 총혐기성균의 변화양상과 유사한 것으로 관찰되었다. 장내 미생물의 변화는 당뇨가 유발된 50일에 당뇨-대조군에 비하여 민들레 잎-열수 추출물 군과 일-에틸아세테이트 추출물군에서 Lactobacillus 증가가 현저하였으며, E. cofi 감소는 잎과 뿌리의 열수 추출물군과 에틸아세테이트 추출물군이 당뇨-대조군과 유사한 수준이며 특히 열수 추출물군의 E. coli억제효과가 관찰되었다. 본 실험 결과 민들레추출물이 당뇨유발된 흰쥐의 장내 미생물에 유익한 효과로 숙주의 감염에 대한 저항력이 있는 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제21권9호
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• pp.885-892
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• 2011

The bacterial communities in the intestinal tracts of earthworm were investigated by culture-dependent and -independent approaches. In total, 72 and 55 pure cultures were isolated from the intestinal tracts of earthworms under aerobic and anaerobic conditions, respectively. Aerobic bacteria were classified as Aeromonas (40%), Bacillus (37%), Photobacterium (10%), Pseudomonas (7%), and Shewanella (6%). Anaerobic bacteria were classified as Aeromonas (52%), Bacillus (27%), Shewanella (12%), Paenibacillus (5%), Clostridium (2%), and Cellulosimicrobium (2%). The dominant microorganisms were Aeromonas and Bacillus species under both aerobic and anaerobic conditions. In all, 39 DNA fragments were identified by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis. Aeromonas sp. was the dominant microorganism in feeds, intestinal tracts, and casts of earthworms. The DGGE band intensity of Aeromonas from feeds, intestinal tracts, and casts of earthworms was 12.8%, 14.7%, and 15.1%, respectively. The other strains identified were Bacillus, Clostridium, Enterobacter, Photobacterium, Pseudomonas, Shewanella, Streptomyces, uncultured Chloroflexi bacterium, and uncultured bacterium. These results suggest that PCR-DGGE analysis was more efficient than the culturedependent approach for the investigation of bacterial diversity and the identification of unculturable microorganisms.

• BMB Reports
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• 제56권1호
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• pp.15-23
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• 2023

After birth, animals are colonized by a diverse community of microorganisms. The digestive tract is known to contain the largest number of microbiome in the body. With emergence of the gut-brain axis, the importance of gut microbiome and its metabolites in host health has been extensively studied in recent years. The establishment of organoid culture systems has contributed to studying intestinal pathophysiology by replacing current limited models. Owing to their architectural and functional complexity similar to a real organ, co-culture of intestinal organoids with gut microbiome can provide mechanistic insights into the detrimental role of pathobiont and the homeostatic function of commensal symbiont. Here organoid-based bacterial co-culture techniques for modeling host-microbe interactions are reviewed. This review also summarizes representative studies that explore impact of enteric microorganisms on intestinal organoids to provide a better understanding of host-microbe interaction in the context of homeostasis and disease.

• Journal of Animal Science and Technology
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• 제65권5호
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• pp.1105-1109
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• 2023

Pedi coccus acidilactici CACC 537 was isolated from canine feces and reported to have probiotic properties. We aimed to characterize the potential probiotic properties of this strain by functional genomic analysis. Complete genome sequencing of P. acidilactici CACC 537 was performed using a PacBio RSII and Illumina platform, and contained one circular chromosome (2.0 Mb) with a 42% G + C content. The sequences were annotation revealed 1,897 protein-coding sequences, 15 rRNAs, and 56 tRNAs. It was determined that P. acidilactici CACC 537 genome carries genes known to be involved in the immune system, defense mechanisms, restriction-modification (R-M), and the CRISPR system. CACC 537 was shown to be beneficial in preventing pathogen infection during the fermentation process, help host immunity, and maintain intestinal health. These results provide for a comprehensive understanding of P. acidilactici and the development of industrial probiotic feed additives that can help improve host immunity and intestinal health.

• Asian-Australasian Journal of Animal Sciences
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• 제31권3호
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• pp.429-438
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• 2018

Objective: Although the efficacy of Rubus coreanus (RC) byproducts as a feed additive has been recognized, its effects on intestinal microorganisms and the immune system are still unknown. Methods: Six-week-old male rats were treated with 0.5% RC (T1), 1.0% RC (T2), and 1.5% RC (T3) for 4 weeks. Results: We found that treatment with RC byproducts significantly increased the daily gain of body weight and feed intake. Treg-cell differentiation was enhanced in the mesenteric lymph nodes and spleen from the rats fed with RC byproducts. Illumina sequencing showed that bacteria in the phylum Firmicutes decreased and while those in the phylum Bacteroidetes increased in RC-treated groups. Particularly, the pathogenic microorganisms in the family Peptococcaceae decreased, and the non-pathogenic families Lachnospiraceae and S24-7 increased. Quantitative polymerase chain reaction analysis showed that the RC byproducts increased the lactic acid bacteria Bifidobacterium spp., Oscillospira spp., Leuconostoc citreum, and Weissella cibaria in a concentration-dependent manner. Conclusion: RC byproducts may be effective in immunomodulation by affecting intestinal microorganisms.