• Asian-Australasian Journal of Animal Sciences
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• v.15 no.6
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• pp.912-924
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• 2002

Disease susceptibility is linked to nutritional status for a wide range of human and animal diseases. Nutritional status can influence both resistance (ability to resist the pathogen) and resilience (ability to tolerate or ameliorate the effects of the pathogen). This review focuses on the nutritional modulation of gastro-intestinal nematode infection in domestic ruminants, primarily sheep. It highlights the duality of the adverse consequences of infection on host nutritional status and the adverse consequences of poor host nutritional status on resistance to infection. Central to both phenomena is the complex, gut-based immune response to gastrointestinal nematode infection. The potential for strategic nutritional supplementation to enhance host resistance and resilience is reviewed together with recent findings on responses to increased ME supply, and long term effects on host immunity of short term protein supplementation.

• Korean Journal of Veterinary Research
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• v.53 no.4
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• pp.199-205
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• 2013

Avian pathogenic Escherichia coli (APEC) is a causative agent for a number of extra intestinal diseases and account for significant losses to the poultry industry. Since protective immunity against APEC is largely directed to virulence antigens, we have individually expressed four different viulence antigens, papA, papG, IutA, and CS31A, using an attenuated Salmonella Typhimurium and a plasmid pBB244. Following oral immunization of mice with combination of two or four of these strains, serum IgG and mucosal IgA responses were elicited against each antigen represented in the mixture. The antigen-specific mucosal IgA responses were significantly higher in the group of mice immunized with the heat-labile Escherichia coli enterotoxin B subunit (LTB) strain than those in the group of mice immunized without the LTB strain. While, there was no significant difference between these two groups in antigen-specific serum IgG responses. The results showed that LTB could act as mucosal immune adjuvant. To assess the nature of immunity, the distribution of antigen-specific IgG isotypes was analyzed. All groups promoted Th1-type immunity as determined by the IgG2a/IgG1 ratio. Thus, our findings provided evidence that immunization with a combination of several vaccine strains is one of the strategies of developing effective vaccines against APEC.

• Korean Journal of Poultry Science
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• v.26 no.3
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• pp.149-170
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• 1999

Protozoa of the genus Eimeria are the etiologic agents of avian coccidiosis, the most economically important Parasitic disease for the poultry industry. Coccidia multiply in intestinal epithelial cells of a wide range of hosts, including livestock in addition to poultry. Chemotherapy is extensively used to control coccidiosis. However, development of drug resistance by Eimeria parasites, the intensive cost and labor involved in the identification of new anticoccidial compounds and public awareness of drug residues in foods warrant alternative methods to prevent coccidiocic in the fast growing poultry industry. For these reasons, there is a great interest in developing vaccines against avian coccidiosis. Live Eimeria vaccines confer protective immunity, however a significant disadvantage of using these types of vaccines is their pathogenicity. Live parasites with attenuated pathogenicity also usually produce immunity but may revert back to a pathogenic form and may be contaminated with other pathogenic organisms. Killed Eimeria vaccines are safer but, unlike live attenuated vaccines, are not able to generate cytotoxic T lymphocyte responses. Recombinant vaccines are biochemically purified proteins produced by genetic engineering that consist of particular epitopes or metabolites of Eimeria. Unlike live attenuated organisms, recombinant vaccines do not possess as much risk and generally are able to induce both humoral and cell mediated immunity. DNA vaccines consist of genes encoding immunogenic proteins of pathogens that are directly administered into the host in a manner that the gene is expressed and the resulting protein generates a protective immune response. Although all of these different types of vaccines have been applied to coccidiosis, this disease continues to cause substantial morbidity and mortality in the poultry industry. Future development of an effective vaccine against coccidiosis will depend on further investigation of protective immunity to Eimeria infection and identification of important immundgenic parasite molecules.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.9
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• pp.1320-1325
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• 2005

A 2${\times}$3 factorial arrangement of treatments was used to determine the effects of olaquindox and cyadox on immune response of Landrace${\times}$Large-White geld piglets that had been orally given 10$^{10}$ CFU of Escherichia coli (E. coli, O$_{139}$:K$_{88}$). Factors included (1) E. coli inoculation or control, and (2) no antimicrobials, 100 mg/kg olaquindox and 100 mg/kg cyadox in the basal diet respectively. E. coli inoculums were orally administered 7 days after the diets were supplemented with olaquindox and cyadox. The effects of the two antimicrobials were assessed in terms of: (1) average daily gain (ADG), (2) systemic immune response (the number of white blood cells and lymphocytes, leukocyte bactericidal capacity, lymphocyte proliferation response to PHA, immunoglobulin concentrations, and total serous hemolytic complement activity), and (3) intestinal mucosal immunity including the number of intraepithelial lymphocytes (IELs) and immunoglobulin A secreting cells (ASCs) in the intestinal lamina propria. E. coli inoculation reduced ADG (p<0.05) during the period of d 0 to d 14 after the challenge while the antimicrobial supplementations improved ADG (p<0.01) during the experiment. ADG in cyadox-supplemented pigs was higher (p<0.05) than that in olaquindox-supplemented pigs. The antimicrobials decreased IEL and ASC counts in the jejunum and ileum (p<0.01) while E. coli inoculation caused them to increase (p<0.01). Jejunal ASCs in the cyadox-supplemented pigs were lower (p<0.05) than those in the olaquindox-supplemented. E. coli elicited increase (p<0.05) in white blood cell counts, leukocyte bactericidal capacity, lymphocyte proliferation rate, serous IgA concentrations, and serous hemolytic complement activity. The antimicrobials decreased the measured systemic immune parameters, but not significantly (p>0.05). The data suggest that olaquindox and cyadox suppress E. coli-induced immune activation, especially intestinal mucosal immune activation, which may be involved in the observed growth promotion.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.10
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• pp.1478-1485
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• 2017

Objective: The effects of vaccinating 18-day-old chicken embryos with the combination of recombinant Eimeria profilin plus Clostridium perfringens (C. perfringens) NetB proteins mixed in the Montanide IMS adjuvant on the chicken immune response to necrotic enteritis (NE) were investigated using an Eimeria maxima (E. maxima)/C. perfringens co-infection NE disease model that we previously developed. Methods: Eighteen-day-old broiler embryos were injected with $100{\mu}L$ of phosphate-buffered saline, profilin, profilin plus necrotic enteritis B-like (NetB), profilin plus NetB/Montanide adjuvant (IMS 106), and profilin plus Net-B/Montanide adjuvant (IMS 101). After post-hatch birds were challenged with our NE experimental disease model, body weights, intestinal lesions, serum antibody levels to NetB, and proinflammatory cytokine and chemokine mRNA levels in intestinal intraepithelial lymphocytes were measured. Results: Chickens in ovo vaccinated with recombinant profilin plus NetB proteins/IMS106 and recombinant profilin plus NetB proteins/IMS101 showed significantly increased body weight gains and reduced gut damages compared with the profilin-only group, respectively. Greater antibody response to NetB toxin were observed in the profilin plus NetB/IMS 106, and profilin plus NetB/IMS 101 groups compared with the other three vaccine/adjuvant groups. Finally, diminished levels of transcripts encoding for proinflammatory cytokines such as lipopolysaccharide-induced tumor necrosis $factor-{\alpha}$ factor, tumor necrosis factor superfamily 15, and interleukin-8 were observed in the intestinal lymphocytes of chickens in ovo injected with profilin plus NetB toxin in combination with IMS 106, and profilin plus NetB toxin in combination with IMS 101 compared with profilin protein alone bird. Conclusion: These results suggest that the Montanide IMS adjuvants potentiate host immunity to experimentally-induced avian NE when administered in ovo in conjunction with the profilin and NetB proteins, and may reduce disease pathology by attenuating the expression of proinflammatory cytokines and chemokines implicated in disease pathogenesis.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.4
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• pp.596-608
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• 2003

Weaning is a complex phase when the mammal suffers the action of different stressors that contribute to negatively affect the efficiency of the intestinal mucosa and of the whole local integrated system, that acts as barrier against any nocuous agent. The components of this barrier are mechanical, chemical, and bacteriological; immunological and not. The development of contact with a saprophyte microflora and the maintenance of feed intake after the interruption of motherly nutrition are essential for the maturation of an equilibrated local immune function and for a functional integrity of villi. Opportunities and limits of some dietary strategies that can contribute to reduce negative effects of weaning on health and performance are discussed. Knowledges on the possible mechanism of action of probiotics are upgraded, particularly for their supposed role in the balance between different immune functions (effectory/regulatory). Some tools to control pathogen microflora are reviewed (acids, herbs, immunoglobulin sources) and practical feeding systems are proposed.

• YAKHAK HOEJI
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• v.54 no.4
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• pp.232-239
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• 2010

Stems and roots of Acanthopanax koreanum Nakai were extracted with water and treated on immune cells in order to determine their immunomodulatory activites. Various Th-1 type cytokines were measured using ELISA including interleukin (IL)-2, IL-12, interferon-gamma (IFN-$gamma$), and tumor necrosis factor-alpha (TNF-$\alpha$) secreted by dendritic cells, T-cells, intestinal epithelial cells, natural killer cells, and macrophages. As a result, there was a significant increase in IL-12 and IFN-$\gamma$, secretion, but there was no change in the secretion of TNF-$alpha$. Additionally T-cells slightly increased the secretion of IL-2, but there was a significant increase of IL-2 in intestinal epithelial cells. Therefore, our results suggest that A. koreanum Nakai may act as an immunomodulator by stimulating the cell-mediated immunity which can help the immune system defend against infections or cancer cells.

• Journal of Dairy Science and Biotechnology
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• v.37 no.2
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• pp.94-101
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• 2019

Probiotics stabilize intestinal microflora, reduce constipation, reduce decay by inhibiting harmful bacteria, and prevent diseases. Probiotics have also been studied for their possible roles in immune activation, treatment of cancer, remediation of cholesterol, treatment of diabetes, alleviation of allergies, and relief of lactose intolerance. However, recent data concerning the side effects of probiotics have prompted debate regarding their efficacy and safety. Major adverse events associated with probiotics are gastrointestinal symptoms, such as diarrhea, gastrointestinal disorders, and vomiting, along with skin rash and urticaria. Probiotics occasionally cause sepsis in infants with poor immunity and elderly people with severe diseases. In contrast to previous studies that described the efficacy of probiotics in intestinal regulation, some recent studies have reported that the activity of intestinal microbes becomes weak as a result of the influx of probiotics. The data indicate that the safety of probiotics is not guaranteed and that further investigations are needed.

• Journal of Yeungnam Medical Science
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• v.38 no.1
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• pp.27-33
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• 2021

The gut is a complex organ that has played an important role in digestion, absorption, endocrine functions, and immunity. The gut mucosal barriers consist of the immunologic barrier and nonimmunologic barrier. During critical illnesses, the gut is susceptible to injury due to the induction of intestinal hyperpermeability. Gut hyperpermeability and barrier dysfunction may lead to systemic inflammatory response syndrome. Additionally, gut microbiota are altered during critical illnesses. The etiology of such microbiome alterations in critical illnesses is multifactorial. The interaction or systemic host defense modulation between distant organs and the gut microbiome is increasingly studied in disease research. No treatment modality exists to significantly enhance the gut epithelial integrity, permeability, or mucus layer in critically ill patients. However, multiple helpful approaches including clinical and preclinical strategies exist. Enteral nutrition is associated with an increased mucosal barrier in animal and human studies. The trophic effects of enteral nutrition might help to maintain the intestinal physiology, prevent atrophy of gut villi, reduce intestinal permeability, and protect against ischemia-reperfusion injury. The microbiome approach such as the use of probiotics, fecal microbial transplantation, and selective decontamination of the digestive tract has been suggested. However, its evidence does not have a high quality. To promote rapid hypertrophy of the small bowel, various factors have been reported, including the epidermal growth factor, membrane permeant inhibitor of myosin light chain kinase, mucus surrogate, pharmacologic vagus nerve agonist, immune-enhancing diet, and glucagon-like peptide-2 as preclinical strategies. However, the evidence remains unclear.

• Animal Bioscience
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• v.35 no.8
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• pp.1109-1120
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• 2022

Antibiotics used to be supplemented to animal feeds as growth promoter and as an effective strategy to reduce the burden of pathogenic bacteria present in the gastro-intestinal tract. However, in-feed antibiotics also kill bacteria that may be beneficial to the animal. Secondly, unrestricted use of antibiotics enhanced the antibiotic resistance in pathogenic bacteria. To overcome above problems, scientists are taking a great deal of measures to develop alternatives of antibiotics. There is convincing evidence that probiotics could replace in-feed antibiotics in poultry production. Because they have beneficial effects on growth performance, meat quality, bone health and eggshell quality in poultry. Better immune responses, healthier intestinal microflora and morphology which help the birds to resist against disease attack were also identified with the supplementation of probiotics. Probiotics establish cross-feeding between different bacterial strains of gut ecosystem and reduce the blood cholesterol level via bile salt hydrolase activity. The action mode of probiotics was also updated according to recently published literatures, i.e antimicrobial substances generation or toxin reduction. This comprehensive review of probiotics is aimed to highlight the beneficial effects of probiotics as a potential alternative strategy to replace the antibiotics in poultry.