• Korean Journal of Microbiology
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• v.11 no.4
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• pp.175-180
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• 1973

This study was attempted to see more clear relationships among the enterobacteria, especially between the intestinal normal flora and pathogenic bacteria. It has been known that some intestinal normal flora produce the bactrial metabolites that are harmful to other enteric bacteria. One of the metabolites is known as colicin, the protein fraction, which possesses certain degree of inhibitory effect against other bacterial growth fraction, whih possesses certain degree of inhibitory effect against other bacterial growth. As a preliminary study for a colicin purification, the antagonistic effect of E, coli to groups of Salmonella and Shigella has been studied by means of in vitro quantitative culture method. 1. E.coli showed definite inhibitory effects aganist both Salmonella and Shigella groups in the mixture of two organisms. 2. The inhibitory effects of E.coli in the E.coli-Salmonella and the E.coli-Shigella mixture occurred from 4 hours incubation following the inoculation. 3. Even the complete inhibition of pathogenic enteric bacterial growth was noticed in the E.coli-Salmonella mixture at overnight incubation. 4. Among the diluted mixtures, 1:100, 1:1,000, and 1:10,000, survival rate of pathogenic enteric bacteria in the mixtures with E.coli showed least affected at the 1:1,000 dilution. 5. It was found that the antagonistic effect aganist groups of Salmonella-shigella was depending upon the groups of the genera.

• Journal of Veterinary Science
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• v.24 no.3
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• pp.23.1-23.16
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• 2023

Background: Irritable bowel syndrome (IBS) is a functional bowel disorder (FBD). Objectives: To assess the therapeutic effects of paeoniflorin (PF) on IBS in rats. Method: Sixty male Sprague-Dawley rats were randomly divided into normal, model, positive drug, low-dose PF, medium-dose PF and high-dose PF groups (n = 10). After gavage for 2 consecutive weeks, the effect of PF on abdominal pain symptoms was assessed based on the abdominal withdrawal reflex (AWR) score, fecal water content and pathological changes in colon tissues. D-lactate, interleukin-1β (IL-1β), transforming growth factor-β (TGF-β) and tumor necrosis factor-α (TNF-α) were detected by enzyme-linked immunosorbent assay, and phosphorylated nuclear factor kappa B (p-NF-κB) p65 was detected by Western blotting. The abundance and diversity changes of intestinal flora were explored using 16S ribosomal RNA sequencing. Result: In PF groups, the mucosal morphology of colon tissues was intact, and the glands were arranged neatly and structured clearly, without obvious inflammatory cell infiltration. Compared with the model group, PF groups had significantly elevated pain threshold, and mRNA and protein levels of zonula occludens-1 (ZO-1) and occludin, decreased AWR score at 20 mmHg pressure, fecal water content, mRNA levels of IL-1β, TGF-β, and TNF-α, protein level of p-NF-κB p65 and level of serum D-lactate, and reduced levels of serum IL-1β, TGF-β, and TNF-α (p < 0.05, p < 0.01). PF groups had higher abundance of Lactobacillus, Akkermansia, Alistipes, and Bacteroides, but lower abundance of Desulfovibrio, Parasutterella, and Enterococcus than those of the model group. Conclusions: PF exerts therapeutic effects on IBS in rats probably by regulating the intestinal flora, and then up-regulating the expressions of ZO-1 and occludin in colon tissue while down-regulating the levels of IL-1β, TGF-β, TNF-α, D-lactate and p-NF-κB p65.

• Journal of Nutrition and Health
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• v.32 no.2
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• pp.129-136
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• 1999

This study was conducted to investigate the effect of fructooligosaccharide on intestinal flora, lipid metabolism and immune response. Thirty two male rats of Sprague-Dawley strain were divided into two groups according to body weight. Each group was fed the diet containing 2% cholesterol or the normal diet, respectively for 4 weeks. Each group was again divided into two sub-groups and they were fed with the diet containing 5% of sucrose and fructooligosaccharide, respectively for 8 weeks. The number of bifidobacteria slight increased, but not significantly, in oligosaccharide groups. Plasma total lipid concentration in cholesterol group was signficantly increased compared to the value in normal group. Dietary oligosaccharide decreased plasma total lipid concentration and triglyceride concentrations in normal group, but not in cholesterol group. Fecal lipid excretion was higher in cholesterol group than in normal group. Fecal cholesterol concentration in cholesterol-oligosaccharide group was significantly increased compared to other groups. Cholesterol had slight effects on TBARS and the immune status, but dietary oligosaccharide had no effects on these variables. The results in this study suggest that dietary oligosaccharide had no effect on serum and liver profiles of rats fed high cholesterol diet but increases the fecal cholesterol excretion.

• Biomolecules & Therapeutics
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• v.7 no.4
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• pp.385-389
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• 1999

The injibitory effect of Bacillus licheniformis AJ isolated from genitourinary normal flora as a new probiotics on the growth of diarrheal pathogens was studied. This B. licheniformis AJ inhibited the growth of E.coli O-157. Salmonella typhi and Shigella sonnei as well as the infectivity of rotavirus. However, it did not inhibit the growth of Helicobacter pyloriand human intestinal bacteria although it inhibited the harmful enzyme activity of human intestinal bacteria. B. licheniformis AJ seems to excret heat-lable growth-inhibitory protein, bacteriocin, into the media. These results suggest that B. lichenoformis AJ could be used as a new type of probiotics.

• Journal of Life Science
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• v.27 no.11
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• pp.1290-1298
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• 2017

Intestinal microbiota is an important factor in the development of immune defense mechanisms in the human body. Treatments with anticancer agents, such as 5-Fluorouracil, Cisplatin, and Oxaliplatin, significantly change the temporal stability and environment of intestinal bacterial flora. The anticancer treatment chemotherapy often depresses the immune system and induces side effects, such as diarrhea. This study investigated the effects anticancer agents have on the intestinal microbial ecosystems of patients with gastric cancer. An exploration of the diversity and temporal stability of the dominant bacteria was undertaken using a DGGE with the 16S rDNA gene. Researchers collected stool samples from patients zero, two and eight weeks after the patients started chemotherapy. After the treatment with anticancer agents, the bacteria strains Sphingomonas paucimobilis, Lactobacillus gasseri, Parabacteroides distasonis and Enterobacter sp. increased. This study focused on the survival of the beneficial microorganisms Bifidobacterium and Lactobacillus in the intestines of cancer patients. The administration of antigastric cancer agents significantly decreased Lactobacillus and Bifidobacterium populations and only moderately affected the main bacterial groups in the patients' intestinal ecosystems. The results showed the versatility of a cultivation independent-PCR DGGE analysis regarding the visual monitoring of ecological diversity and anticancer agent-induced changes in patients' complex intestinal microbial ecosystems.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.9 no.2
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• pp.162-168
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• 2006

Purpose: Microbial colonization of the intestine begins just after birth and development of the normal flora is a gradual process. The first bacteria colonizing the intestine in newborns are Staphylococcus, Enterobacteriaceae and Streptococcus. For several days after birth, the number of Bifidobacterium spp. increase. The aim of this study was to investigate the changes of microflora for seven days postnatally in neonatal stool. Methods: Fifteen neonates (breast : formula : mixed feeding 1 : 8 : 6, vaginal delivery : cesarean section 3 : 12) who were born at the Kangdong Sacred Heart Hospital, Hallym University were enrolled. First meconium and stools of postnatal 1-, 3-, and 7-day were innoculated. Blood agar plates for total aerobes, trypton bile X-glucuronide agar for E. coli, phenylethyl alcohol agar for gram positive anaerobes, MRS agar for Lactobacillus spp., bifidobacterium selective agar for Bifidobacterium spp. and cefoxitin-cycloserine-fructose agar for Clostridium difficile were used in the general incubator ($CO_2$ free incubator), $CO_2$ incubator or the anaerobic chamber for 48 or 72 hours at $37^{\circ}C$ and then colony forming units were counted. Results: No microflora was identified in the first meconium. Total aerobes, E. coli, and gram positive anaerobes were significantly increased with advancing postnatal days. In only one baby, Lactobacillus acidophilus was detected $2{\times}10^5CFU/g$ in the seven-day stool. Bifidobacterium spp. was detected in two babies. Clostridium difficile was not detected during the seven days. There were no significant differences in the bowel flora depending on the delivery pattern and feeding method. Conclusion: This study shows many changes in the intestinal normal flora in neonatal stool during seven days postnatally. If these findings are confirmed with larger studies, the data may be preliminary findings to support use of probiotics in neonates.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.1
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• pp.166-176
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• 2020

Objective: An experiment was conducted to determine the effects of L-arginine (L-Arg) and N-carbamoylglutamic acid (NCG) on the growth, metabolism, immunity and community of cecal bacterial flora of weanling and young rabbits. Methods: Eighteen normal-grade male weanling Japanese White rabbits (JWR) were selected and randomly divided into 6 groups with or without L-Arg and NCG supplementation. The whole feeding process was divided into weanling stage (day 37 to 65) and young stage (day 66 to 85). The effects of L-Arg and NCG on the growth, metabolism, immunity and development of the ileum and jejunum were compared via nutrient metabolism experiments and histological assessment. The different communities of cecal bacterial flora affected by L-Arg and NCG were assessed using high-throughput sequencing technology and bioinformatics analysis. Results: The addition of L-Arg and NCG enhanced the growth of weanling and young rabbit by increasing the nitrogen metabolism, protein efficiency ratio, and biological value, as well as feed intake and daily weight gain. Both L-Arg and NCG increased the concentration of immunoglobulin A (IgA), IgM, and IgG. NCG was superior to L-Arg in promoting intestinal villus development by increasing villus height, villus height/crypt depth index, and reducing the crypt depth. The effects of L-Arg and NCG on the cecal bacterial flora were mainly concentrated in different genera, including Parabacteroides, Roseburia, dgA-11_gut_group, Alistipes, Bacteroides, and Ruminococcaceae_UCG-005. These bacteria function mainly in amino acid transport and metabolism, energy production and conversion, lipid transport and metabolism, recombination and repair, cell cycle control, cell division, and cell motility. Conclusion: L-Arg and NCG can promote the growth and immunity of weanling and young JWR, as well as effecting the jejunum and ileum villi. L-Arg and NCG have different effects in the promotion of nutrient utilization, relieving inflammation and enhancing adaptability through regulating microbial community.

• Journal of Microbiology
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• v.39 no.3
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• pp.154-161
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• 2001

In recent years, colon cancer has been reported to be one of the most important causes of cancer morbidity and mortality in Korea. Epidemiological and experimental studies suggest that lactic acid bacteria (LAB) used to ferment dairy products inhibits colon carcinogenesis. The present study was designed to determine whether the colon cancer inhibitory effect of LAB (Bifidobacterium longum Hy8001; Bif and Lactobacillus acidophilus HY2l04; Lac) of Korean origin, is associated with intestinal microflora composition and certain enzyme activity in rats treated with azoxymethane (AOM). At five weeks of age, SD rats were divided at random into four (AOM alone, Bif, Lac, and Bif+Lac) groups. Oral administration of lactic acid bacteria cultures were performed daily until the termination of the study. Two weeks later all animals were given a subcutaneous injection of AOM dissolved in normal saline at a dose of 15 mg/kg of body weight once weekly for 2 weeks. Every two weeks for 10 weeks, five of the rats in each group were randomly chosen for fecal specimen collection. The fecal specimens were used for assay of $\beta$-glucuronidase and nitroreductase, and analysis of intestinal microflora composition. The activity of $\beta$-glucuronidase which plays an important role in the production of the carcinogenic metabolite of azoxymethane was remarkably increased in the AOM alone group after AOM injection and maintained the high level during the experiment. However, LAB inhibited the AOM-induced increase in $\beta$-glucuronidase activity. Nitroreductase activity decreased by 30-40% in LAB treated groups in comparison with that of the AOM alone group. The results of the present study suggest that LAB inhibits colon carcinogenesis by modulating the metabolic activity of intestinal micro-flora and improving the composition of intestinal microflora.

• Korean Journal of Microbiology
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• v.16 no.4
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• pp.161-169
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• 1978

Escherichiae-like organisms were isolated from rectal specimens of 56 children who were either in preschool age or in elementary school. The isolated strains were subjected to tests to screen enteropathogens producing heat-labile enterotoxin and susceptibility test to various antibiotics by disc diffusion method on agar plates. Production of heat-labile enterotoxin by the strains was assyed in the sensitive and reproducible cultured adrenal tumor cell system. The assay was sterodogenesis of the cell in the presence of heat-labile enterotoxin. Among 56 strains, gave positive reaction in the test of toxin production. This meant that about 10% of the children population objected to the study harbored the toxigenic strain of enteropathogenes. Some of these toxigenic strains were resistant to the antibiotics employed in the test. This study suggested that considerable population in Korea may harbor entertoxigenic E. coli as a part of intestinal normal flora. The toxigenic strains which are resistant to antibiotics may bring issue of public health in the future.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.163.2-163.2
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• 2003

The genera Bifidobacterium is a member of the normal intestinal flora in humans, and important in food industry. In order to test the genetic identity of this bacterial genera, four primers originated from rice genome (SRILS Microbial $UniPrimers^{TM}$ kit) were used in molecular typing of 7 Bifidobacterial species and 20 isolates from various source. SRILS Microbial $UniPrimers^{TM}$ kit were effectively applied to genomic fingerprinting of various organism such as plant, animal and microorganism. (omitted)