• Journal of Dairy Science and Biotechnology
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• v.39 no.2
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• pp.63-67
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• 2021

Antibiotics are widely used to improve productivity in the dairy industry. However, the inappropriate use of antibiotics causes the deterioration in the quality of dairy products undergoing fermentation and maturation. Hence, probiotic use is emerging as an alternative to curb the increased utilization of antibiotics. Probiotics are defined as "living microorganisms that, when administered in appropriate amounts, confer health benefits on the host." They may improve host disease resistance by regulating intestinal microflora balance and promote animal growth and development. In the dairy industry, probiotics have been studied to increase milk production by improving digestion in dairy cows, enhance the content of dairy components such as milk fat and protein, reduce the risk of mastitis in cows, and increase calf weight. Thus, the use of probiotics can improve the production and safety of dairy products. However, some probiotics are still unstable during storage and have low quality and safety issues. Therefore, to reduce the use of antibiotics in the dairy industry, probiotics should be developed and produced considering the above-mentioned problems.

• Journal of Dairy Science and Biotechnology
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• v.37 no.1
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• pp.27-32
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• 2019

Fermented milk has been developed with its functionalities, and its health-promoting ability has been spotlighted due to its relationship with diseases such as cancer, cardiovascular disease, and diabetes, and gut microbiota. As national burden of cardiovascular disease increases over time, there is a need to prevent hypercholesterolemia. To achieve that, gut microbiota, which is altered by host's diet and environment, plays important roles in lowering cholesterol in the blood. Moreover, fermented milk may be effective as a cholesterol-lowering agent by altering gut microbiota composition. Gut microbiota may alter not only functions of the fermented milk but also bio-accessibility of functional materials. These results suggested that gut microbiota composition influences the impact of fermented milk. Thus, we should understand how functional materials are degraded by gut microbiota and absorbed into the gut.

• Journal of Dairy Science and Biotechnology
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• v.39 no.1
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• pp.20-26
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• 2021

Lactase (β-galactosidase) is abundant in the small intestine during early childhood and gradually decreases with age. Lactic acid bacteria (LAB) present in yogurt could survive in the stomach, and lactase produced by these LAB can aid in lactose breakdown in the small intestine, thereby reducing lactose intolerance. This study aims to provide preliminary data for development of lactose-free yogurts for the elderly, and investigate the effect of lactose-hydrolyzed milk on the growth of starter cultures. The pH during yogurt fermentation using lactose-free milk was slightly higher at 2 and 4 h of incubation, but reached 4.5 at the end of incubation, similar to that of the yogurt prepared from regular milk. The number of viable cells of Streptococcus thermophilus reached 108 CFU/mL after 2 h of incubation and increased to 109 CFU/mL after 4 h of incubation. During yogurt fermentation, the viable cells of Lactobacillus species and Bifidobacterium longum did not affect lactose hydrolysis. Although lactose-hydrolyzed milk did not promote the growth of starter cultures, manufacturing yogurt with lactose-free milk could be beneficial for the intestinal health of lactose-sensitive elderly.

• Journal of Animal Reproduction and Biotechnology
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• v.37 no.2
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• pp.149-154
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• 2022

Busulfan is the most commonly used drug for preconditioning during the transplantation of hematopoietic stem cells and male germ cells. Here, we describe side effects of high doses of busulfan in male mongrel dogs. Busulfan was intravenously administered to three groups of dogs at doses of 10, 15, and 17.5 mg/kg body weight. The total white blood cell, neutrophil, eosinophil, lymphocyte, monocyte, and platelet counts steadily reduced in a dose-dependent manner following busulfan treatment. The white blood cell, neutrophil, and monocyte counts recovered after 6 weeks of busulfan treatment, however, the eosinophil, lymphocyte, and platelet counts remained unaltered. Additionally, there was one fatality in the each of the groups that were administered 15 and 17.5 mg/kg busulfan. The gross lesions included severe hemorrhage in the stomach, intestinal tracts, mesentery and urinary bladder. Microscopic investigation revealed severe pulmonary edema and hemorrhage in the lungs, and severe multifocal to coalescing transmural hemorrhage in the intestines and urinary bladder. These results indicated that treatment with busulfan at doses higher than 15 mg/kg initiates severe bleeding in the internal organs and can have fatal results.

• Journal of Animal Science and Technology
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• v.64 no.3
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• pp.443-461
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• 2022

This study was conducted to assess the effects of the dietary supplementation of riboflavin (as a bile salt hydrolase [BSH] inhibitor) and Bacillus subtilis on growth performance and woody breast of male broilers challenged with Eimeria spp. Intestinal bacteria, including supplemented probiotics, can produce BSH enzymes that deconjugate conjugated bile salts and reduce fat digestion. A 3 × 2 × 2 (riboflavin × Bacillus subtilis × Eimeria spp. challenge) factorial arrangement of treatments in randomized complete block design was used. On d 14, birds were gavaged with 20× doses of commercial cocci vaccine (Coccivac^R -B52, Merck Animal Health, Omaha, NE). Dietary treatment of riboflavin and B. subtilis did not affect body weight (BW), body weight gain (BWG), and feed conversion (FCR) d 0 to 14 and overall d 0 to 41. Eimeria spp challenge reduced BWG, feed intake (FI), and increased FCR between d 14 to 28, but increased BWG and lowered FCR between d 28 to 35. There were no effects of the Eimeria spp. challenge on the overall d 0 to 41 FCR and FI, but BWG was reduced. Eimeria spp. challenge increased the abdominal fat pad weight and slight woody breast incidences on processed birds on d 42. Dietary inclusion of B. subtilis and riboflavin at tested levels did not help birds to mitigate the negative impact of Eimeria spp. challenge to enhance the growth performance.

• Food Science of Animal Resources
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• v.43 no.1
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• pp.157-169
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• 2023

Effects of culture supernatants of Lactobacillus reuteri MG5346 (CS-MG5346) on receptor activator of nuclear factor-kappa B ligand (RANKL)-induced osteoclastogenesis were examined. CS-MG5346 treatment up to 400 ㎍/mL significantly reduced tartrate-resistant acid-phosphatase (TRAP) activity, the phenotype biomarker of osteoclast, without affecting cell viability. CS-MG5346 inhibited the expression of osteoclast specific transcriptional factors (c-fos and nuclear factor-activated T cells c1) and their target genes (TRAP, cathepsin, and matrix metallo-proteinase-9) in a dose-dependent manner (p<0.05). The administration of L. reuteri MG5346 (2×10⁸ CFU/day) for 8 wks significantly improved furcation involvement, but no difference was observed in alveolar bone loss in ligature-induced experimental periodontitis rats. The elevated RANKL/osteoprotegerin ratio, the biomarker of periodontitis, was significantly lowered in the gingival tissue by administration of L. reuteri MG5346 (p<0.05). L. reuteri MG5346 showed excellent stability in simulated stomach and intestinal fluids and did not have antibiotic resistance. Based on the results, L. reuteri MG5346 has the potential to be a promising probiotic strain for oral health.

• Parasites, Hosts and Diseases
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• v.61 no.3
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• pp.298-303
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• 2023

This study aimed to describe a rare case of gnathostomiasis in the vocal cord. A 54-yearold Chinese woman living in Korea visited with a chief complaint of voice change at the outpatient department of otorhinolaryngology in Hallym Sacred Heart Hospital, Hallym University on August 2, 2021. She had eaten raw conger a few weeks before the voice change developed, but her medical history and physical examinations demonstrated neither gastrointestinal symptoms nor other health problems. A round and red cystic lesion, recognized in the anterior part of the right vocal cord, was removed using forceps and scissors through laryngeal microsurgery. The histopathological specimen of the cyst revealed 3 cross-sections of a nematode larva in the lumen of the cyst wall composed of inflammatory cells and fibrotic tissues. They differ in diameter, from 190 ㎛ to 235 ㎛. They showed characteristic cuticular layers with tegumental spines, somatic muscle layers, and gastrointestinal tracts such as the esophagus and intestine. Notably, intestinal sections consisted of 27-28 lining cells containing 0-4 nuclei per cell. We tentatively identified the nematode larva recovered from the vocal cord cystic lesion as the thirdstage larva of Gnathostoma, probably G. nipponicum or G. hispidum, based on the sectional morphologies.

• Journal of Animal Science and Technology
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• v.65 no.1
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• pp.271-274
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• 2023

Lactic acid bacteria (LAB) have been reported to possess various beneficial properties and are commonly used as probiotics. LAB play a crucial role in milk fermentation, industrial lactic acid fermentation, and health and medicine. Limosilactobacillus fermentum isolated from fermented dairy and food products is considered as 'Generally Recognized as Safe' by FDA. Limosilactobacillus fermentum plays an important role in modulation of the intestinal microbiota, enhancing the host immune system and improving feed digestibility. We isolated a probiotic candidate that was identified and named Limosilactobacillus fermentum JNU532. In a previous report, cell-free culture of L. fermentum JNU532 exhibited anti-melanogenic and antioxidant activities. In this study, we present the complete genome assembly of the bacterial strain JNU532. The final genome consists of one circular chromosome (2,077,416 base pairs) with a guanine + cytosine (GC) ratio of 51.5%.

• IMMUNE NETWORK
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• v.23 no.1
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• pp.6.1-6.24
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• 2023

Intestinal microorganisms interact with various immune cells and are involved in gut homeostasis and immune regulation. Although many studies have discussed the roles of the microorganisms themselves, interest in the effector function of their metabolites is increasing. The metabolic processes of these molecules provide important clues to the existence and function of gut microbes. The interrelationship between metabolites and T lymphocytes in particular plays a significant role in adaptive immune functions. Our current review focuses on 3 groups of metabolites: short-chain fatty acids, bile acids metabolites, and polyamines. We collated the findings of several studies on the transformation and production of these metabolites by gut microbes and explained their immunological roles. Specifically, we summarized the reports on changes in mucosal immune homeostasis represented by the Tregs and Th17 cells balance. The relationship between specific metabolites and diseases was also analyzed through latest studies. Thus, this review highlights microbial metabolites as the hidden treasure having potential diagnostic markers and therapeutic targets through a comprehensive understanding of the gut-immune interaction.

• Parasites, Hosts and Diseases
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• v.55 no.4
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• pp.451-455
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• 2017

Echinostoma cinetorchis is an oriental intestinal fluke causing significant pathological damage to the small intestine. The aim of this study was to determine a full-length cDNA sequence of E. cinetorchis endoribonuclease (RNase H; EcRNH) and to elucidate its molecular biological characters. EcRNH consisted of 308 amino acids and showed low similarity to endoribonucleases of other parasites (<40%). EcRNH had an active site centered on a putative DDEED motif instead of DEDD conserved in other species. A recombinant EcRNH produced as a soluble form in Escherichia coli showed enzymatic activity to cleave the 3'-O-P bond of RNA in a DNA-RNA duplex, producing 3'-hydroxyl and 5'-phosphate. These findings may contribute to develop antisense oligonucleotides which could damage echinostomes and other flukes.