• Journal of Microbiology
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• 제39권3호
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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.

• 한방비만학회지
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• 제9권1호
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• pp.1-14
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• 2009

Complex microbial communities play an important role in the human health and co-evolved with human in the form of symbiosis. Many literatures provide new evidences that the increased prevalence of obesity cannot be attributed solely to changes in the human genome, nutritional habits, or reduction of physical activity in our daily lives. The intestinal flora was recently proposed as an environmental factor responsible for the control of body weight and energy metabolism. A number of studies suggest that the modulation of gut microbiota affects host metabolism and has an impact on energy storage and demonstrated a role for the gut microbiota in weight gain, fat increase, and insulin resistance. Variations in microbiota composition are found in obese humans and mice and the microbiota from an obese mouse confers an obese phenotype when transferred to an axenic mouse. As well, the gut microbial flora plays a role in converting nutrients into calories. Specific strategies for modifying gut microbiota may be a useful means to treat or prevent obesity. Dietary modulations of gut microbiota with a view to increasing bifidobacteria have demonstrated to reduce endotoxemia and improve metabolic diseases such as obesity. The fermentation of medicinal herbs is intended to exert a favorable influence on digestability, bioavailability and pharmacological activity of herbal extract. Therefore we also expect that the fermented herbal extracts may open up a new area to treat obesity through modulating gut microbiota.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제9권2호
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• pp.162-168
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• 2006

목 적: 자궁 내에서 태아의 소화기는 무균상태에 있다가 출생 후 신생아기에 점차 장내세균의 집락화가 이루어진다. 출생 초기에 처음으로 나타나는 세균은 Staphylococcus, Enterobacteriaceae, Streptococcus가 있으며, 이후 Bifidobacterium spp.와 같은 혐기성 세균이 나타난다. 이에 저자들은 정상 신생아의 대변에서 생후 1주일 동안 장내세균총의 분포와 변화를 규명하고자 하였다. 방 법: 한림의대 강동성심병원에서 출생한 정상 신생아 15명(자연분만 3명, 제왕절개 12명)(모유수유 1명, 분유수유 8명, 혼합수유 6명)을 대상으로 하였다. 출생 첫 대변과 1일, 3일, 7일째의 대변을 채취하였다. 대변 배양 배지와 조건를 달리하여 호기성균(blood agar plate), E. coli (trypton bile X-glucuronide 배지), 그람 양성 혐기성균(phenylethyl alcohol agar), lactobacillus (MRS 배지), Bifidobacterium spp. (bifidobacterium selective agar), Clostridium difficile (cefoxitincycloserine-fructose agar)을 검출하여 배양된 균 집락의 수를 측정하여 기록하였다. 결 과: 출생 첫 대변에서는 균이 거의 검출되지 않았다. 호기성균, E. coli, 그람 양성 혐기성균은 출생 시부터 생후 7일까지 유의하게 증가하였다(p<0.05). Lactobacilli는 한명의 신생아에서 생후 7일에 검출되었다. Bifidobacterium spp.은 2명에서 검출되었다. Clostridium difficile은 생후 7일까지 검출되지 않았다. 분만 방법과 수유 방법에 따른 균 집락의 차이는 없었다. 결 론: 정상 신생아에서 생후 1주일 동안 장내세균총의 다양한 변화를 관찰할 수 있었다. 앞으로 생후 1주일 이후의 장내세균총의 변화와 더 많은 환아에서의 연구를 진행한다면 생균제 사용에 도움이 되리라 생각된다.

• 한국수산과학회지
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• 제56권1호
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• pp.89-98
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• 2023

We evaluated the effects of prebiotic (mannan oligosaccharides, Mos) and probiotic diet supplements on growth performance, innate immunity, antioxidant activity, and intestinal changes in the microbial flora of red seabream Pagrus major. A basal diet (Con) was formulated to meet the nutrient requirement of red seabream. The dietary starch in Con was replaced with 0.6% Mos, Lactobacillus plantarum, Bacillus subtilis, B. licheniformis and probiotic mixture (labeled as Mos, Pro-LP, Pro-BS, Pro-BL and Pro-Mix, respectively). We stocked 450 fish in 18 polypropylene tanks (400 L) in triplicate groups per dietary treatment. The fish were fed one of the diets twice (08:30, 18:30 h) a day for 63 days. Lysozyme activity was significantly higher in all the supplemented groups than that of the Con group. The immunoglobulin level of Pro-Mix, anti-protease activity of Pro-BL, and glutathione peroxidase and superoxide dismutase activity of Pro-BS, Pro-BL and Pro-Mix groups were significantly higher than those of the Con group. The ratio of total Vibrio/heterotrophic marine bacteria counts was significantly lower in Pro-LP, Pro-BL and Pro-Mix groups than that of the Con group. Therefore, dietary supplementation of Mos and probiotics to improves immune response and antioxidant enzyme activity and inhibits Vibrio bacteria in the intestine.

• 한국식품영양과학회지
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• 제39권6호
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• pp.820-825
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• 2010

본 연구에서는 비만과 관련된 요소 중 하나인 장내 균총을 개선하고자, 식이섬유소가 풍부하고 저칼로리인 담자균류 추출물을 이용하여 in vitro 상에서 비만 관련 장내 미생물에 대한 항균활성을 조사하였다. 항균성 담자 균류 소재 탐색결과 석이버섯 자실체와 운지버섯 균사체의 추출물을 선발하였고, 선발된 담자균류 소재 추출물의 특성을 분석한 결과 열에 대단히 안정하였고, pH에도 비교적 안정한 것으로 나타났다. 또한 rat을 이용한 동물실험에서 석이버섯 80% 에탄올 추출물 투여군이 고지방식이만 투여한 군에 비하여, 장내 균총에서 Bifidobacterium spp.가 증가되었고, Clostridium spp.와 Eubacterium spp.는 감소된 것으로 나타났다. 석이버섯과 운지버섯 추출물이 첨가된 기능성 음료를 제조하고자 관능평가를 실시한 결과, 운지버섯 균사체 배양액에 석이버섯 추출물을 3% 첨가한 실험구가 가장 좋은 평가를 받았다. 이러한 결과를 토대로 석이버섯과 운지버섯 추출물이 장내 균총 개선을 위한 기능성 식품소재로 활용될 수 있을 것으로 생각된다.

• 농업과학연구
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• 제44권4호
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• pp.558-565
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• 2017

This study was conducted to determine the effect of inoculation of microorganism isolated from pig feces on nutrient contents of fermented hulless barley. The microbial flora in feces of a total of four crossbred piglets ($Landrace{\times}Yorkshire{\times}Duroc$) was analyzed by 16s rRNA sequencing. The most abundant strain was then selected for fermentation of hulless barley. Lactobacillus plantarum (L. plantarum) was dominant (64.56%) in intestinal microbial flora in the pig feces. The selected candidate strain showed significantly higher survival rate at pH 7 than at pH 2.5 and 3.0 (p < 0.05). Incubated culture containing the candidate strain showed an increased growth rate with lower pH levels after 7.5 h incubation compared to initial incubation period (p < 0.05). When compared with commercial multiple probiotics which were used as control, the selected strain showed faster growth rate at 5 h post-incubation (p < 0.05). During the fermentation period, neither inoculated nor non-inoculated control hulless barley showed any change in pH value. Crude fat, fiber and ash contents were lower (p < 0.05) in hulless barley inoculated by the selected strain compared to control. However, moisture, energy, NDF and ADF were not affected by the inoculation of strain or fermentation period. Lactic acid was increased and acetic acid was decreased in the hulless barley inoculated with the selected strain during the fermentation period (p < 0.05). Taken together, our results suggest that L. plantarum derived from the pigs could be utilized as a new microorganism for manufacturing fermented feed stuffs.

• 한국식품과학회지
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• 제27권2호
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• pp.225-229
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• 1995

저칼로리 감미료로서 장내 미생물 균총을 개선한다고 알려진 대두 올리고당을 전처리 및 Steffen법을 이용하여 대두 침지액으로부터 분리, 회수하였다. 전처리로서 pH를 $3.5{\sim}4.0$으로 조절하거나, 염화칼슘을 당 대비 8%(w/w)를 첨가하여 대두 침지액 중에 함유된 단백질을 약 $25{\sim}30%$가량 제거할 수 있었다. 또한 대두 침지액에 염화칼슘과 산화칼슘 분말을 각각 당 대비 약 20%, $100{\sim}120%$씩 첨가한 후 $5^{\circ}C$에서 20분 동안 반응시키는 Steffen법을 이용하면 대두 침지액 중에 존재하는 대두 올리고당의 약 85%를 saccharate 형태로 분리, 회수할 수가 있었다. 이산화탄소로 당을 탈착시켜 회수한 결과 최종적으로 약 80%의 수율로 당을 회수할 수가 있었으며 단백질은 약 80% 정도 제거할 수가 있었다. 회수된 당액의 당조성은 대두 침지액과 유사하였다.

• Journal of Microbiology and Biotechnology
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• 제27권8호
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• pp.1392-1400
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• 2017

Galactooligosaccharides (GOSs) are known to be selectively utilized by Bifidobacterium, which can bring about healthy changes of the composition of intestinal microflora. In this study, ${\beta}-GOS$ were synthesized using bifidobacterial ${\beta}-galactosidase$ (G1) purified from recombinant E. coli with a high GOS yield and with high productivity and enhanced bifidogenic activity. The purified recombinant G1 showed maximum production of ${\beta}-GOSs$ at pH 8.5 and $45^{\circ}C$. A matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis of the major peaks of the produced ${\beta}-GOSs$ showed MW of 527 and 689, indicating the synthesis of ${\beta}-GOSs$ at degrees of polymerization (DP) of 3 and DP4, respectively. The trisaccharides were identified as ${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-glucopyranose, and the tetrasaccharides were identified as ${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-glucopyranose. The maximal production yield of GOSs was as high as 25.3% (w/v) using purified recombinant ${\beta}-galactosidase$ and 36% (w/v) of lactose as a substrate at pH 8.5 and $45^{\circ}C$. After 140 min of the reaction under this condition, 268.3 g/l of GOSs was obtained. With regard to the prebiotic effect, all of the tested Bifidobacterium except for B. breve grew well in BHI medium containing ${\beta}-GOS$ as a sole carbon source, whereas lactobacilli and Streptococcus thermophilus scarcely grew in the same medium. Only Bacteroides fragilis, Clostridium ramosum, and Enterobacter cloacae among the 17 pathogens tested grew in BHI medium containing ${\beta}-GOS$ as a sole carbon source; the remaining pathogens did not grow in the same medium. Consequently, the ${\beta}-GOS$ are expected to contribute to the beneficial change of intestinal microbial flora.

• Journal of Microbiology
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• 제43권4호
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• pp.345-353
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• 2005

The complex ecosystem of intestinal micro flora is estimated to harbor approximately 400 different microbial species, mostly bacteria. However, studies on bacterial colonization have mostly been based on culturing methods, which only detect a small fraction of the whole microbiotic ecosystem of the gut. To clarify the initial acquisition and subsequent colonization of bacteria in an infant within the few days after birth, phylogenetic analysis was performed using 16S rDNA sequences from the DNA iso-lated from feces on the 1st, 3rd, and 6th day. 16S rDNA libraries were constructed with the amplicons of PCR conditions at 30 cycles and $50^{\circ}C$ annealing temperature. Nine independent libraries were produced by the application of three sets of primers (set A, set B, and set C) combined with three fecal samples for day 1, day 3, and day 6 of life. Approximately 220 clones ($76.7\%$) of all 325 isolated clones were characterized as known species, while other 105 clones ($32.3\%$) were characterized as unknown species. The library clone with set A universal primers amplifying 350 bp displayed increased diversity by days. Thus, set A primers were better suited for this type of molecular ecological analysis. On the first day of the life of the infant, Enterobacter, Lactococcus lactis, Leuconostoc citreum, and Streptococcus mitis were present. The largest taxonomic group was L. lactis. On the third day of the life of the infant, Enterobacter, Enterococcus faecalis, Escherichia coli, S. mitis, and Streptococcus salivarius were present. On the sixth day of the life of the infant, Citrobacter, Clostridium difficile, Enterobacter sp., Enterobacter cloacae, and E. coli were present. The largest taxonomic group was E. coli. These results showed that microbiotic diversity changes very rapidly in the few days after birth, and the acquisition of unculturable bacteria expanded rapidly after the third day.

• Animal Bioscience
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• 제34권2호
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• pp.243-255
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• 2021

Objective: Deoxynivalenol (DON) and zearalenone (ZEN) are mycotoxins that frequently contaminate maize and grain cereals, imposing risks to the health of both humans and animals and leading to economic losses. The gut microbiome has been shown to help combat the effects of such toxins, with certain microorganisms reported to contribute significantly to the detoxification process. Methods: We examined the cecum contents of three different dietary groups of pigs (control, as well as diets contaminated with 8 mg DON/kg feed or 0.8 mg ZEN/kg feed). Bacterial 16S rRNA gene amplicons were acquired from the cecum contents and evaluated by next-generation sequencing. Results: A total of 2,539,288 sequences were generated with ~500 nucleotide read lengths. Firmicutes, Bacteroidetes, and Proteobacteria were the dominant phyla, occupying more than 96% of all three groups. Lactobacillus, Bacteroides, Megasphaera, and Campylobacter showed potential as biomarkers for each group. Particularly, Lactobacillus and Bacteroides were more abundant in the DON and ZEN groups than in the control. Additionally, 52,414 operational taxonomic units were detected in the three groups; those of Bacteroides, Lactobacillus, Campylobacter, and Prevotella were most dominant and significantly varied between groups. Hence, contamination of feed by DON and ZEN affected the cecum microbiota, while Lactobacillus and Bacteroides were highly abundant and positively influenced the host physiology. Conclusion: Lactobacillus and Bacteroides play key roles in the process of detoxification and improving the immune response. We, therefore, believe that these results may be useful for determining whether disturbances in the intestinal microflora, such as the toxic effects of DON and ZEN, can be treated by modulating the intestinal bacterial flora.