• Asian-Australasian Journal of Animal Sciences
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• 제30권1호
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• pp.78-84
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• 2017

Objective: The aim of this study was to examine shifts in the composition of the bacterial population in the intestinal tracts (ITs) of weaning piglets by antibiotic treatment using high-throughput sequencing. Methods: Sixty 28-d-old weaning piglets were randomly divided into two treatment groups. The Control group was treated with a basal diet without antibiotics. The Antibiotic group's basal diet contained colistin sulfate at a concentration of 20 g per ton and bacitracin zinc at a concentration of 40 g per ton. All of the pigs were fed for 28 days. Then, three pigs were killed, and the luminal contents of the jejunum, ileum, cecum, and colon were collected for DNA extraction and high-throughput sequencing. Results: The results showed that the average daily weight gain of the antibiotic group was significantly greater (p<0.05), and the incidence of diarrhea lower (p>0.05), than the control group. A total of 812,607 valid reads were generated. Thirty-eight operational taxonomic units (OTUs) that were found in all of the samples were defined as core OTUs. Twenty-one phyla were identified, and approximately 90% of the classifiable sequences belonged to the phylum Firmicutes. Forty-two classes were identified. Of the 232 genera identified, nine genera were identified as the core gut microbiome because they existed in all of the tracts. The proportion of the nine core bacteria varied at the different tract sites. A heat map was used to understand how the numbers of the abundant genera shifted between the two treatment groups. Conclusion: At different tract sites the relative abundance of gut microbiota was different. Antibiotics could cause shifts in the microorganism composition and affect the composition of gut microbiota in the different tracts of weaning piglets.

• Journal of Microbiology and Biotechnology
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• 제34권2호
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• pp.367-378
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• 2024

In this study we sought to elucidate the therapeutic effects of fenchone on constipation-predominant irritable bowel syndrome (IBS-C) and the underlying mechanisms. An IBS-C model was established in rats by administration of ice water by gavage for 14 days. Fenchone increased the reduced body weight, number of fecal pellets, fecal moisture, and intestinal transit rate, and decreased the enhanced visceral hypersensitivity in the rat model of IBS-C. In addition, fenchone increased the serum content of excitatory neurotransmitters and decreased the serum content of inhibitory neurotransmitters in the IBS-C rat model. Meanwhile, western blot and immunofluorescence experiments indicated that fenchone increased the expressions of SCF and c-Kit. Furthermore, compared with the IBS-C model group, fenchone increased the relative abundance of Lactobacillus, Blautia, Allobaculum, Subdoligranulum, and Ruminococcaceae_UCG-008, and reduced the relative abundance of Bacteroides, Enterococcus, Alistipes, and Escherichia-Shigella on the genus level. Overall, fenchone ameliorates IBS-C via modulation of the SCF/c-Kit pathway and gut microbiota, and could therefore serve as a novel drug candidate against IBS-C.

• 한국환경농학회지
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• 제37권2호
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• pp.135-140
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• 2018

한국에서 말벌은 양봉 산업에 큰 영향을 미치는 종이다. 특히 비교적 최근에 전국적으로 번식하는 말벌 종인 등검은말벌 (Vespa velutina nigrithorax)은 작은 체구에도 불구하고 높은 사냥 능력으로 꿀벌을 공격하여 양봉 업계에 큰 피해를 주고 있다. 그러나 이 새로운 침입 종에 대한 연구는 아직 시작단계에 있으며, 본 연구에서는 등검은말벌의 장내 박테리아 군집을 조사하고 이 결과를 꿀벌의 장내 박테리아 군집과 비교하여 등검은말벌의 방제를 위한 자료로 이용하고자 했다. 아시아 말벌과 꿀벌 장의 박테리아 게놈 DNA를 수집하여 16S rDNA를 증폭시켜 가변 부위인 V3, V4 염기서열을 판독 하였다. 계통별 분석결과 목 (order) 수준에서 Flavobacteriales는 등검은말벌에서 가장 우점인 박테리아였고, Aeromonadales와 Pseudomonadales가 그 뒤를 이었다. Flavobacteriaes는 꿀벌의 박테리아 군집과 비교했을 때 등검은말벌에서 증가하였으며, Aeromonadales와 Pseudomonadales는 우점종이지만 꿀벌에 비해 낮은 점유율을 보이는 등 두 개체 간의 차이를 확인할 수 있었다. 한편 이번 연구를 통해 이전에 동정되지 않은 등검은말벌 장 박테리아의 16S rDNA 염기 서열을 분석하였고, 이들 박테리아는 Thalassomonas, Caedobacter, Vampirovibrio, Alkaliphilus 및 Calothrix 속으로 분류되었다.

• Journal of Neurogastroenterology and Motility
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• 제24권4호
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• pp.628-642
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• 2018

Background/Aims A Subset of patients with irritable bowel syndrome (IBS) may have mild inflammation due to immune activation. Toll-like receptors (TLRs) and cytokines may cause intestinal inflammation. We studied their expression in relation to gut microbiota. Methods Expression of TLRs and cytokines was assessed in 47 IBS patients (Rome III) and 25 controls using quantitative real-time polymerase chain reaction. Immunohistochemistry was further performed to confirm the expression of TLR-4 and TLR-5. Results Of 47 patients with IBS, 20 had constipation (IBS-C), 20 diarrhea (IBS-D), and 7 unclassified (IBS-U). The mRNA levels of TLR-4 and TLR-5 were up-regulated in IBS patients than controls (P = 0.013 and P < 0.001, respectively). Expression of TLR-4 and TLR-5 at protein level was 4.2-folds and 6.6-folds higher in IBS-D than controls. The mRNA levels of IL-6 (P = 0.003), C-X-C motif chemokine ligand 11 (CXCL-11) (P < 0.001) and C-X-C motif chemokine receptor 3 (CXCR-3) (P < 0.001) were higher among IBS patients than controls. Expression of IL-6 (P = 0.002), CXCL-11 (P < 0.001), and CXCR-3 (P < 0.001) were up-regulated and IL-10 (P = 0.012) was down-regulated in IBS-D patients than controls. Positive correlation was seen between TLR-4 and IL-6 (P = 0.043), CXCR-3, and CXCL-11 (P = 0.047), and IL-6 and CXCR-3 (P = 0.003). Stool frequency per week showed positive correlation with mRNA levels of TLR-4 (P = 0.016) and CXCR-3 (P = 0.005), but inversely correlated with IL-10 (P = 0.002). Copy number of Lactobacillus (P = 0.045) and Bifidobacterium (P = 0.011) showed correlation with IL-10 in IBS-C, while Gram-positive (P = 0.031) and Gram-negative bacteria (P = 0.010) showed correlation with CXCL-11 in IBS-D patients. Conclusions Altered immune activation in response to dysbiotic microbiota may promote intestinal inflammation in a subset of patients with IBS.

• 생명과학회지
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• 제29권8호
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• pp.922-940
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• 2019

비만은 에너지 섭취와 소비의 불균형으로 인해 유발되는 비정상적인 지방 축적으로, 근래에 다양한 만성질환을 초래하는 주요 국제 보건 문제로 부상하였다. 이러한 이유로, 비만 문제에 대한 여러 해결책들이 제시되고 있다. 에너지를 저장하며 내분비 작용을 하는 백색 지방과 달리 열을 생성하여 에너지를 발산하는 두 종류의 지방조직인 갈색 지방과 베이지색 지방이 성인에 존재하며 외부 자극에 의해 유도될 수 있다는 것이 밝혀진 이래로, 이들은 비만 치료의 유망한 표적으로서 각광받고 있다. 이러한 외부 자극 중, 인간 장관계에서 인간과 공존하는 장내 미생물총은 다양한 대사 작용에 참여하며, 이를 조절하는 것이 여러 대사 질환의 치료에 유력한 작용을 할 것으로 보인다. 따라서, 다양한 연구에서 항비만 치료가 장내 미생물 환경 전환이나 갈색 지방 조직 활성화에 미치는 영향에 초점을 맞추고 있다. 본 총설에서는 비만과 체중 증가, 대사 질환을 해소하는 것으로 알려진 자극과, 장내 미생물총의 변화나 갈색지방의 활성화를 야기하는 자극과, 이 자극들과 장내 미생물총의 조작, 지방조직의 갈색화 사이에서 알려져 있거나 있을 수 있는 상관관계를 중점적으로 다루고자 한다.

• Asian-Australasian Journal of Animal Sciences
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• 제33권6호
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• pp.992-1001
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• 2020

Objective: This study was conducted to investigate the effects of hot-melt extruded ZnO nano-particles (HME-ZnO) as an alternative for P-ZnO on growth performance, nutrient digestibility, Zn bioavailability, intestinal microbiota, and intestinal morphology of weanling pigs. Methods: A total of 450 piglets (Landrace×Yorkshire×Duroc) were randomly allotted to five treatments based on initial body weight and sex. The experimental diets were fed in a meal form as phase 1 from d 0 to 14 and phase 2 from d 15 to 28. Treatments were the control diet without ZnO supplementation, the diet containing 2,500 ppm Zn as ZnO, and three diets containing 500, 1,000, or 2,500 ppm Zn as HME-ZnO. Results: The overall result showed a higher (p<0.01) average daily gain in weanling pigs fed ZnO-supplemented diets in comparison to the control diet. There was a decrease (p<0.01) in fecal score in the ZnO-supplemented diets. Dietary supplementation of ZnO improved (p<0.05) crude protein digestibility. The weanling pigs fed the P-ZnO diet had a lower (p<0.01) Zn digestibility in the feces than HME-ZnO supplemented treatments. Weanling pigs fed diets supplemented with ZnO had greater (p<0.05) Lactobacillus spp. populations and lower Clostridium spp. (p<0.05) and Coliforms (p<0.01) populations in the ileum. Weanling pigs fed diets supplemented with increasing concentrations of HME-ZnO linearly decreased Clostridium spp. (p<0.05) and Coliforms (p<0.01) in the ileum. Lower (p<0.05) Clostridium spp. and Coliforms counts in the colon were observed in pigs fed with ZnO-supplemented diets. Weanling pigs fed diets supplemented with ZnO showed a greater (p<0.01) villus height in the duodenum. Conclusion: Dietary supplementation of HME-ZnO and P-ZnO showed a potential to improve the digestibility of protein, intestinal Coliform and Clostridium, villus height in duodenum and ileum. Moreover, HME-ZnO showed a higher Zn digestibility compared with P-ZnO.

• Journal of Dairy Science and Biotechnology
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• 제38권2호
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• pp.70-88
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• 2020

대부분의 스타터 배양균은 유산균(LAB)군(group)에 속하며 미국 식품의약국(FDA)과 유럽식품안전청(EFSA)에 의해 안전하다고 인정받고 있다. 그러나, LAB는 항생제 내성(antibiotic resistance) 유전자를 위한 내적 또는 외적 저장소로 작용할 수 있다. 하지만 저항 유전자 전달이 수직이기 때문에 이 사실은 그 자체가 안전상의 문제가 아닐 수도 있다. 그럼에도 불구하고 외부 유전적 요소는 심각한 안전 문제를 나타내는 인체 장내 미생물뿐만 아니라 병원균의 저항성 수평 전달에 유리한 변화를 유도할 수 있다. 항생제 내성을 가진 유산균의 일부 속(genus)에는 발효육 및 유제품에서 분리된 Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Pediococcus, Streptococcus 등이 포함된다. 현재 WHO는 식품산업에서 사용되는 LAB는 저항이 없어야 한다고 권고하고 있다. 다행히도 한국의 식품의약품안전처가 인정한 프로바이오틱스 균주 중 Enterococcus에 해당되는 균주는 E. faecium과 E. faecalis인데, 2019년 4월 1일부터 E. faecium과 E. faecalis의 독성인자와 항생제 내성전달인자 모두 없다고 인정된 경우에면 사용이 허가된다. 따라서 LAB의 산업적 중요성을 고려할 때 앞으로 인체와 동물장관 유래의 LAB은 체계적인 탐색 및 동정, 병원성 및 항생제 내성 유전자의 확인, 식품 및 가축사료 첨가제로의 활용, 안전성 평가연구는 계속 필요하다고 사료된다.

• 한국수산과학회지
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• 제48권4호
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• pp.447-453
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• 2015

We determined the optimal culture conditions for obtaining the maximum number of intestinal bacteria from the olive flounder Paralichthys olivaceus, and studied bacterial diversity using both culture-dependent and culture-independent methods. Using six culture conditions, mean bacterial numbers were greater than $10^6$ per gram of gut mucus, regardless of the medium. However, the bacterial diversity, based on colony morphology, appeared much higher on Marine agar (MA) and Zobell 2216 agar than on other media. We found eight and 17 cultured bacterial phylotypes with 99% minimum similarity in gut mucus grown on MA and tryptic soy agar, respectively. Furthermore, we used genomic DNA extracted from gut mucus to generate 78 random clones, which were grouped into 25 phylotypes. Of these, six were affiliated with Firmicutes, Actinobacteria, and Verrucomicrobia, and were not found using our culture-dependent methods. Consequently, we believe that Marine agar and Zobell 2216 agar are optimal media for culturing diverse intestinal microbes; we also discovered several novel sequences not previously recognized as part of the gut microbiota of olive flounder.

• Journal of Dairy Science and Biotechnology
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• 제39권3호
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• pp.94-103
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• 2021

The lack of an effective treatment for Alzheimer's disease (AD) stems primarily from incomplete understanding of AD's causes. A rapidly growing number of scientific reports highlight important roles played by peripheral infections and intestinal bacterial flora in pathological and physiological functions involving the microbiome-intestine-brain axis. The microbiome controls basic aspects of the central nervous system (CNS), immunity, and behavior, in health and disease. Changes in the density and composition of the microbiome have been linked to disorders of the immune, endocrine, and nervous systems, including mood changes, depression, increased susceptibility to stressors, and autistic behaviors. There is no doubt that in patients with AD, restoration of the intestinal microbiome to a composition reminiscent of that found in healthy adult humans will significantly slow the progression of neurodegeneration, by ameliorating inflammatory reactions and/or amyloidogenesis. In the near future, better understanding of bidirectional communication between the brain and microbiota will allow the development of functional diets using specific probiotic bacteria.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제22권4호
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• pp.330-340
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• 2019

Human breast milk contains numerous biomolecules. Human milk oligosaccharides (HMOs) are the third most abundant component of breast milk, after lactose and lipids. Amongst the synthetized HMOs, 2'-fucosyllactose (2'-FL) and lacto-N-neotetraose (LNnT) are widely studied and are considered safe for infant nutrition. Several studies have reported the health benefits of HMOs, which include modulation of the intestinal microbiota, anti-adhesive effect against pathogens, modulation of the intestinal epithelial cell response, and development of the immune system. The amount and diversity of HMOs are determined by the genetic background of the mothers (HMO secretors or non-secretors). The non-secretor mothers secrete lower HMOs than secretor mothers. The breastfed infants of secretor mothers gain more health benefit than those of non-secretor mothers. In conclusion, supplementation of infant formula with 2'-FL and LNnT is a promising innovation for infant nutrition.