• Journal of Ginseng Research
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• v.46 no.6
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• pp.780-789
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• 2022

Background: Incretin impairment, characterized by insufficient secretion of L-cell-derived glucagon-like peptide-1 (GLP-1), is a defining step of type 2 diabetes mellitus (T2DM). Ginsenoside compound K (CK) can stimulate GLP-1 secretion; however, the potential mechanism underlying this effect has not been established. Methods: CK (40 mg/kg) was administered orally to male db/db mice for 4 weeks. The body weight, oral glucose tolerance, GLP-1 secretion, gut microbiota sequencing, bile acid (BA) profiles, and BA synthesis markers of each subject were then analyzed. Moreover, TGR5 expression was evaluated by immunoblotting and immunofluorescence, and L-cell lineage markers involved in L-cell abundance were analyzed. Results: CK ameliorated obesity and impaired glucose tolerance in db/db mice by altering the gut microbiota, especially Ruminococcaceae family, and this changed microbe was positively correlated with secondary BA synthesis. Additionally, CK treatment resulted in the up-regulation of CYP7B1 and CYP27A1 and the down-regulation of CYP8B1, thereby shifting BA biosynthesis from the classical pathway to the alternative pathway. CK altered the BA pool by mainly increasing LCA and DCA. Furthermore, CK induced L-cell number expansion leading to enhanced GLP-1 release through TGR5 activation. These increases were supported by the upregulation of genes governing GLP-1 secretion and L-cell differentiation. Conclusions: The results indicate that CK improves glucose homeostasis by increasing L-cell numbers, which enhances GLP-1 release through a mechanism partially mediated by the gut microbiota-BA-TGR5 pathway. Therefore, that therapeutic attempts with CK might be useful for patients with T2DM.

• Journal of Microbiology and Biotechnology
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• v.29 no.9
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• pp.1369-1374
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• 2019

We isolated Lactobacillus mucosae NK41 and Bifidobacterium longum NK46 from human feces, which induced BDNF expression in corticosterone-stimulated SH-SY5Y cells, and examined their anti-depressive effects in mice. NK41, NK46, and their (1:1) mixture significantly mitigated immobilization stress (IS)-induced anxiety-like/depressive behaviors, hippocampal $NF-{\kappa}B$ activation, BDNF expression, $Iba1^+$ cell population, and blood corticosterone, $TNF-{\alpha}$, IL-6, and lipopolysaccharide levels. Furthermore, they inhibited colitis marker $NF-{\kappa}B$ activation, and $TNF-{\alpha}$ expression in mice with IS-induced anxiety/depression. They additionally suppressed gut Proteobacteria and Bacteroidetes populations and bacterial lipopolysaccharide production. These findings suggest that NK41 and NK46 may alleviate anxiety/depression and colitis by suppressing gut dysbiosis.

• Clinical and Experimental Pediatrics
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• v.60 no.5
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• pp.145-150
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• 2017

Purpose: The gut microbiota can influence several diseases through immune modulation; however, the exact role of microbes such as Clostridium difficile and the relationship between microbiota colonization and allergic diseases are not well known. This study aimed to determine the relationship between C. difficile colonization and/or infection (CDCI) during infancy and allergic diseases during early childhood. Methods: Infants 1-12 months of age presenting changes in bowel habits for more than 2 weeks were enrolled in this study. After dividing them into 2 groups according to the presence and absence of C. difficile, the risk of allergic disease development during childhood was identified and compared. Results: Sixty-five patients were included in this study; 22 (33.8%) were diagnosed with CDCI. No significant differences were observed in baseline characteristics between the C. difficile-positive and-negative groups except for antibiotic exposure (22.7% vs. 60.5%, P=0.004). Compared to the C. difficile-negative group, the risk of developing at least one allergic disease was higher in the C. difficile-positive group after adjusting other variables (adjusted odds ratios, 5.61; 95% confidence interval, 1.52-20.74; P=0.007). Furthermore, food allergies were more prevalent in the C. difficile-positive group (P=0.03). Conclusion: CDCI during infancy were associated with a higher risk of developing allergic diseases during early childhood. These results suggest that CDCI during infancy might reflect the reduced diversity of the intestinal microbiota, which is associated with an increased risk of allergic sensitization. To identify the underlying mechanism, further investigation and a larger cohort study will be needed.

• Korean Journal of Poultry Science
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• v.49 no.2
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• pp.125-137
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• 2022

This study aimed to determine the effects of dietary microalgae (Tetradesmus sp. (TO)) on intestinal immunity and microbiota of pre-starter broilers. One hundred and twenty 1-day-old birds (Ross 308) were allocated to two dietary treatment groups with six blocks in a randomized complete block design. The two experimental diets consisted of a corn-soybean meal-based basal diet and a diet with 0.5% TO powder instead of cornstarch in the basal diet. After feeding the experimental diets for ten days, all birds' body weight and feed intake were measured, and representative eight birds were selected from each treatment group. Small intestinal lamina propria cells were isolated using flow cytometry to examine the frequency of immune cells. Cecal feces were harvested for 16s rRNA gut microbiota analysis and fecal IgA levels. Here, we found that 0.5% TO supplementation increased CD3⁺CD4⁺ T cells in the small intestine, but decreased CD3⁺CD8⁺ T cells in the small intestine. Gut microbial analysis showed that TO supplementation significantly increased the alpha diversity of the gut microbiome. Taxonomic analysis showed that TO treatment increased the abundance of Firmicutes and decreased that of Bacteroidetes at the phylum level. The distribution of Enterobacteriaceae containing many harmful bacteria at the family level, was lower in the TO group. In the LEfSe analysis, the TO group had a significantly enriched abundance of Agathobaculum at the genus level. Overall, results show that Tetradesmus sp. supplementation influences intestinal T-cell immunity and induces the expansion of beneficial gut microbes in pre-starter broiler chickens.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.120-120
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• 2018

Intestinal microbiota is strongly connected to health of host. It has been reported that not only metabolic disease like diabetes and obesity, but psychological diseases are affected by composition of intestinal microbiota. To figure it out the importance of the composition and relationship between disease and microbiota, intensive researches have done with human and experimental animals. But, the composition of the intestinal microbiota could be affected by several factors such as experimental environments, feeding, water, and bedding. As a result, the data from each experimental group might be diverse. It also affects experiments about biological activities of plant materials. In this study, mouse intestinal bacteria were isolated from fresh feces and identified by 16S rRNA gene to use in biological activities of natural medicines. The fecal supernatant was anaerobically incubated at $37^{\circ}C$ for 48 hours. Colonies were picked up separately and incubated again in same condition to increase quantity to analyze and stock. The bacteria strains were listed up and could be used for many researches including biological activities of plant materials and change in composition of intestinal bacteria itself.

• Microbiology and Biotechnology Letters
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• v.47 no.3
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• pp.423-433
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• 2019

Midgut microbiota is known to play a fundamental role in the biology and physiology of the agricultural pest, Spodoptera litura. This study reports the difference in the larval midgut microbiota of field-caught and laboratory-reared populations of S. litura by performing 16S rDNA amplicon pyrosequencing. Field populations for the study were collected from castor crops, whereas laboratory-reared larvae were fed on a regular chickpea based diet. In total, 23 bacterial phylotypes were observed from both laboratory-reared and field-caught caterpillars. Fisher's exact test with Storey's FDR multiple test correction demonstrated that bacterial genus, Clostridium was significantly abundant (p < 0.05) in field-caught larvae of S. litura as compared to that in the laboratory-reared larvae. Similarly, bacterial genera, such as Bradyrhizobium, Burkholderia, and Fibrisoma were identified (p < 0.05) predominantly in the laboratory-reared population. The Bray-Curtis dissimilarity matrix depicted a value of 0.986, which exhibited the maximum deviation between the midgut microbiota of the laboratory-reared and field-caught populations. No significant yeast diversity was seen in the laboratory-reared caterpillars. However, two yeast strains, namely Candida rugosa and Cyberlindnera fabianii were identified by PCR amplification and molecular cloning of the internal transcribed space region in the field-caught caterpillars. These results emphasize the differential colonization of gut residents based on environmental factors and diet.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.1
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• pp.16-22
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• 2016

The intestinal environment plays a critical role in maintaining swine health. Many factors such as diet, microbiota, and host intestinal immune response influence the intestinal environment. Intestinal alkaline phosphatase (IAP) is an important apical brush border enzyme that is influenced by these factors. IAP dephosphorylates bacterial lipopolysaccharides (LPS), unmethylated cytosine-guanosine dinucleotides, and flagellin, reducing bacterial toxicity and consequently regulating toll-like receptors (TLRs) activation and inflammation. It also desphosphorylates extracellular nucleotides such as uridine diphosphate and adenosine triphosphate, consequently reducing inflammation, modulating, and preserving the homeostasis of the intestinal microbiota. The apical localization of IAP on the epithelial surface reveals its role on LPS (from luminal bacteria) detoxification. As the expression of IAP is reported to be downregulated in piglets at weaning, LPS from commensal and pathogenic gram-negative bacteria could increase inflammatory processes by TLR-4 activation, increasing diarrhea events during this phase. Although some studies had reported potential IAP roles to promote gut health, investigations about exogenous IAP effects or feed additives modulating IAP expression and activity yet are necessary. However, we discussed in this paper that the critical assessment reported can suggest that exogenous IAP or feed additives that could increase its expression could show beneficial effects to reduce diarrhea events during the post weaning phase. Therefore, the main goals of this review are to discuss IAP's role in intestinal inflammatory processes and present feed additives used as growth promoters that may modulate IAP expression and activity to promote gut health in piglets.

• 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

• BMB Reports
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• v.49 no.5
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• pp.263-269
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• 2016

The intestine represents the largest and most elaborate immune system organ, in which dynamic and reciprocal interplay among numerous immune and epithelial cells, commensal microbiota, and external antigens contributes to establishing both homeostatic and pathologic conditions. The mechanisms that sustain gut homeostasis are pivotal in maintaining gut health in the harsh environment of the gut lumen. Intestinal epithelial cells are critical players in creating the mucosal platform for interplay between host immune cells and luminal stress inducers. Thus, knowledge of the epithelial interface between immune cells and the luminal environment is a prerequisite for a better understanding of gut homeostasis and pathophysiologies such as inflammation. In this review, we explore the importance of the epithelium in limiting or promoting gut inflammation (e.g., inflammatory bowel disease). We also introduce recent findings on how small RNAs such as microRNAs orchestrate pathophysiologic gene regulation.

• Journal of Microbiology and Biotechnology
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• v.25 no.9
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• pp.1555-1558
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• 2015

Administration of dietary fibers has various health benefits, mainly by increasing numbers of beneficial bacteria and enhancing production of short-chain fatty acids in the colon. There has been growing interest in the addition of dietary fiber to human diet, due to its prebiotic effects. This study aimed to evaluate the prebiotic activity of inulin using an in vitro batch fermentation system with human fecal microbiota. Fermentation of inulin resulted in a significantly greater ratio of Lactobacillus or Bifidobacteria to Enterobacteria strains as an index of healthy human intestine and elevated butyrate concentration, which are related to improvement of gut health.