• Journal of Radiation Protection and Research
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• v.45 no.4
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• pp.163-170
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• 2020

Background: Gut microflora contributes to the nutritional metabolism of the host and to strengthen its immune system. However, if the intestinal barrier function of the living body is destroyed by radiation exposure, the intestinal bacteria harm the health of the host and cause sepsis. Therefore, this study aims to trace short-term radiation-induced changes in the mouse gut microflora-dominant bacterial genus, and analyze the degree of intestinal epithelial damage. Materials and Methods: Mice were irradiated with 0, 2, 4, 8 Gy X-rays, and the gut microflora and intestinal epithelial changes were analyzed 72 hours later. Five representative genera of Actinobacteria, Firmicutes, and Bacteroidetes were analyzed in fecal samples, and the intestine was pathologically analyzed by Hematoxylin-Eosin and Alcian blue staining. In addition, DNA fragmentation was evaluated by the TdT-mediated dUTP nick-end labeling (TUNEL) assay. Results and Discussion: The small intestine showed shortened villi and reduced number of goblet cells upon 8 Gy irradiation. The large intestine epithelium showed no significant morphological changes, but the number of goblet cells were reduced in a radiation dose-dependent manner. Moreover, the small intestinal epithelium of 8 Gy-irradiated mice showed significant DNA damaged, whereas the large intestine epithelium was damaged in a dose-dependent manner. Overall, the large intestine epithelium showed less recovery potential upon radiation exposure than the small intestinal epithelium. Analysis of the intestinal flora revealed fluctuations in lactic acid bacteria excretion after irradiation regardless of the morphological changes of intestinal epithelium. Altogether, it became clear that radiation exposure could cause an immediate change of their excretion. Conclusion: This study revealed changes in the intestinal epithelium and intestinal microbiota that may pave the way for the identification of novel biomarkers of radiation-induced gastrointestinal disorders and develop new therapeutic strategies to treat patients with acute radiation syndrome.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.6
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• pp.830-835
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• 2004

An experiment of 10 weeks duration was carried out to study the influence of supplemental effective microorganism (EM) culture, yeast culture and enzymes on nutrient digestibility and gut microflora in rabbit gastrointestinal (GI) tract. Twenty four eight to nine weeks old, New Zealand White rabbits were allotted to four dietary treatments; a basal (control) feed, basal feed supplemented with either EM (1%), yeast culture or enzymes (400 ppm). Nutrient flow in digesta and their digestibility at ileum, caecum, colon and in the total tract as well as gut microflora distribution were studied. Feed dry matter was diluted from 92% to about 14% up to the ileum and about 95% of this water was reabsorbed by the colonic rectal segment followed by caecum (25%). EM and yeast improved protein digestibility at a lower rate than enzymes. Ileal, caecal, colonic and total tract digestibility of crude protein with enzymes were higher by 10.8, 9.4, 11.3 and 10.7%, respectively, as compared to the control. Yeast and enzymes increased crude fiber digestibility at ileum, caecum, colon and in the total tract by 8.5, 9.6, 9.0 and 8.3%, respectively, while EM improved them at a lower rate. Irrespective of treatments, total tract digestibility of crude protein (0.698-0.773) and fiber (0.169-0.183) were greater (p<0.05) than the ileal digestibility. Even though a post-caecal protein digestibility was observed, fiber digestion seemed to be completed in the caecum especially with yeast and enzymes. High precaecal digestibility of crude fiber (97%) and protein (95%) were observed even without additives probably due to caecotrophy. EM and yeast culture promoted the growth of lactic acid bacteria especially in the caecum but they did not influence gut yeast and mould. Present findings reveal that even though rabbits digest nutrients efficiently through hind gut fermentation, they can be further enhanced by EM, yeast and enzymes. Of the three additives tested, enzymes found to be the best.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.9
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• pp.1330-1338
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• 2008

This study was conducted to investigate the effects of Acanthopanax senticosus extract (ASE) as a dietary additive on gut microflora in weaned piglets. A total of sixty pigs were weaned at 21 d of age (BW = $5.64{\pm}0.23kg$) and allocated on the basis of BW and litter to three dietary treatments in a randomized complete block design. The dietary treatments were: control group (basal diet), antibiotics group (basal diet+0.02% colistin), and ASE group (basal diet+0.1% ASE). On d 7, 14 and 28 after consuming the experimental diets, five piglets per group were sacrificed and then the contents from the jejunum, ileum and cecum were collected to determine changes in the microbial community by using a polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique and estimating the contents of Lactobacillus and E. coli by in vitro culturing methods. The results showed that the ASE promoted the microflora diversity in the cecum. Enumeration of bacteria in the gut contents showed that the number of Lactobacillus increased (p<0.05), while that of E. coli decreased (p<0.05) when compared with the other 2 groups as the days of age progressed post-weaning. These findings suggested that the ASE, as a substitute for dietary antimicrobial products, could improve the development of the normal gut microflora and suppress bacterial pathogens, and effectively promote a healthy intestinal environment.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.3
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• pp.400-406
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• 2011

An experiment was carried out to assess the effects of xylanase supplementation on the performance, net energy and gut microflora of broilers fed a wheat-based diet. Day-old male broiler chicks were allocated to two dietary treatments. Each treatment was composed of six replicate cages of seven broilers per cage. The diets were wheat-based and offered as mash. The treatments included i) basal diet deficient in metabolizable energy; and ii) basal diet supplemented with a commercial xylanase added at 4,000 U/kg feed. Bird performance, nutrient utilization and gut microbial populations were measured. Heat production and net energy were determined using an auto-control, open circuit respiration calorimetry apparatus. Results showed that exogenous xylanase supplementation improved feed conversion efficiency (p<0.05) and increased diet AME (+4.2%; p<0.05), as well as heat production (HP), net energy for production (NEp), production of $CO_2$, and consumption of $O_2$. The respiratory quotient (RQ) was also increased (p<0.01) by the addition of xylanase. NEp value was increased by 26.1% while daily heat production per kg metabolizable body weight was decreased by 26.2% when the xylanase was added. Xylanase supplementation numerically increased the ileal digestibility of protein and energy by 3 and 6 percentage units respectively (p>0.05). The ileal digestibility of hemicellulose was significantly improved by xylanase addition (p<0.05).

• IMMUNE NETWORK
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• v.12 no.4
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• pp.129-138
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• 2012

Allergic disorders such as atopic dermatitis and asthma are common hyper-immune disorders in industrialized countries. Along with genetic association, environmental factors and gut microbiota have been suggested as major triggering factors for the development of atopic dermatitis. Numerous studies support the association of hygiene hypothesis in allergic immune disorders that a lack of early childhood exposure to diverse microorganism increases susceptibility to allergic diseases. Among the symbiotic microorganisms (e.g. gut flora or probiotics), probiotics confer health benefits through multiple action mechanisms including modification of immune response in gut associated lymphoid tissue (GALT). Although many human clinical trials and mouse studies demonstrated the beneficial effects of probiotics in diverse immune disorders, this effect is strain specific and needs to apply specific probiotics for specific allergic diseases. Herein, we briefly review the diverse functions and regulation mechanisms of probiotics in diverse disorders.

• Journal of Microbiology and Biotechnology
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• v.32 no.12
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• pp.1497-1505
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• 2022

Recently, the concept of personalized nutrition has been developed, which states that food components do not always lead to the same metabolic responses, but vary from person to person. Although this concept has been studied based on individual genetic backgrounds, researchers have recently explored its potential role in the gut microbiome. The gut microbiota physiologically communicates with humans by forming a bidirectional relationship with the micronutrients, macronutrients, and phytochemicals consumed by the host. Furthermore, the gut microbiota can vary from person to person and can be easily shifted by diet. Therefore, several recent studies have reported the application of personalized nutrition to intestinal microflora. This review provides an overview of the interaction of diet with the gut microbiome and the latest evidence in understanding the inter-individual differences in dietary responsiveness according to individual baseline gut microbiota and microbiome-associated dietary intervention in diseases. The diversity of the gut microbiota and the presence of specific microorganisms can be attributed to physiological differences following dietary intervention. The difference in individual responsiveness based on the gut microbiota has the potential to become an important research approach for personalized nutrition and health management, although further well-designed large-scale studies are warranted.

• 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.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.1
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• pp.11-19
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• 2018

The gut microbiome has been studied extensively over the past decade with most scientific reports focused on the adverse role of the gut microbiome on gastrointestinal diseases. For example, the altered gut microbiome exacerbates the development of immune system-mediated damage in many diseases. The most studied pathologies include irritable bowel syndrome, inflammatory bowel diseases, and colitis-associated cancer. On the other hand, intestinal microflora is also beneficial and contributes to the intestinal physiology by the synthesis of vitamins, production of short chain fatty acids and bile acid metabolism, thereby maintaining gut homeostasis. Therefore, the balance between commensal and pathogenic bacteria populations influences mainly the maintenance of intestinal health. Changes in the intestinal microflora have been suspected to be the underlying causes of multiple diseases. Despite the immense amount of published data, the optimal gut microbiome composition is still controversial. This review briefly outlines the connection between the gut microbiome and critical gastrointestinal diseases focusing on three prominent intestinal disorders: irritable bowel syndrome, inflammatory bowel diseases, and colitis-associated cancer disorders. Finally, intervention strategies using natural products for the alleviation of these diseases and the maintenance of a health gut microbiome are suggested.

• Fisheries and Aquatic Sciences
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• v.18 no.4
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• pp.379-385
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• 2015

We studied the effects of the proprietary prebiotic Immunogen$^{(R)}$ on the growth, hematology and gut microbiota of common carp fingerlings. A basal diet was formulated using common feed ingredients and supplemented with Immunogen$^{(R)}$ at concentrations of 0, 5, 10, 20 and $40g\;kg^{-1}$, each of which was tested experimentally on replicated groups of fish. The trials ran for 8 weeks. Common carp fingerlings with an initial weight of $4.82{\pm}0.05g$ were randomly distributed among the experimental tanks at a stocking density of 25 fish per tank. The experimental diets were provided thrice per day; on each occasion the fingerlings were given a weight of feed that amounted to 4% of fish biomass. At the end of the experimental period, we determined the growth performance, feed conversion ratio, hematological parameters, body composition and gut micro-flora parameters of the test fish. Inclusion of $5g\;kg^{-1}$Immunogen$^{(R)}$ in the diet significantly improved growth performance and feed utilization in comparison with controls. However, the whole-body composition of the fish was not significantly influenced by prebiotic inclusion. Inclusion of $5g\;kg^{-1}$ Immunogen$^{(R)}$ significantly increased the total bacterial and Lactobacillus counts in fish intestines, but these bacterial parameters were significantly negatively impacted by higher concentrations of the prebiotic. Red blood cells counts were increased by prebiotic dietary supplementation at concentrations of 5 and $10g\;kg^{-1}$ prebiotic. Glucose and cholesterol levels were elevated by administration of Immunogen$^{(R)}$. Thus, dietary supplementation with $5g\;kg^{-1}$ Immunogen$^{(R)}$ improved fingerling common carp growth performance and feed utilization, and beneficially influenced the gut microflora

• Journal of Microbiology and Biotechnology
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• v.30 no.9
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• pp.1321-1334
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• 2020

Beef, pork, chicken and milk are considered representative protein sources in the human diet. Since the digestion of protein is important, the role of intestinal microflora is also important. Despite this, the pure effects of meat and milk intake on the microbiome are yet to be fully elucidated. To evaluate the effect of beef, pork, chicken and milk on intestinal microflora, we observed changes in the microbiome in response to different types of dietary animal proteins in vitro. Feces were collected from five 6-week-old pigs. The suspensions were pooled and inoculated into four different media containing beef, pork, chicken, or skim milk powder in distilled water. Changes in microbial communities were analyzed using 16S rRNA sequencing. The feces alone had the highest microbial alpha diversity. Among the treatment groups, beef showed the highest microbial diversity, followed by pork, chicken, and milk. The three dominant phyla were Proteobacteria, Firmicutes, and Bacteroidetes in all the groups. The most abundant genera in beef, pork, and chicken were Rummeliibacillus, Clostridium, and Phascolarctobacterium, whereas milk was enriched with Streptococcus, Lactobacillus, and Enterococcus. Aerobic bacteria decreased while anaerobic and facultative anaerobic bacteria increased in protein-rich nutrients. Functional gene groups were found to be over-represented in protein-rich nutrients. Our results provide baseline information for understanding the roles of dietary animal proteins in reshaping the gut microbiome. Furthermore, growth-promotion by specific species/genus may be used as a cultivation tool for uncultured gut microorganisms.