• Journal of Microbiology and Biotechnology
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• v.29 no.9
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• pp.1335-1340
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• 2019

Probiotics, including bacteria and yeast, are live microorganisms that have demonstrated beneficial effects on human health. Recently, probiotic bacteria are constantly being studied and their applications are also being considered in promising adjuvant treatments for various intestinal diseases. Clinical trials and in vivo experiments have extended our current understanding of the important roles that probiotics play in human gut microbiomeassociated diseases. It has been documented through many clinical trials that probiotics could shape the intestinal microbiota leading to potential control of multiple bowel diseases and promotion of overall wellness. In this review, we focused on the relationship between probiotics and the human gut microbiota and its roles in gut microbiome-associated diseases. Here, we also discuss future directions and research areas that need further elucidation in order to better understand the roles of probiotics in the treatment of intestinal diseases.

• Fisheries and Aquatic Sciences
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• v.24 no.9
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• pp.297-310
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• 2021

The rockworm gut flora was identified at each growth stage to elucidate the composition of the bacterial community. The source material was Marphysa sanguinea fed regular feed and fed biofloc at the adult stage in parallel. The systematic bacterial community composition was determined based on the next-generation sequencing method, and alpha diversity and beta diversity were conducted to access the species diversity within and between the bacterial communities, respectively. The composition of the gut flora changed considerably as the rockworms developed. The shift in the gut flora was confirmed at the phylum, family, and genera level of the bacterial communities. The Vibrio species associated with high rockworm mortality occupied 7.7% of the gut flora at the larval stage; however, they disappeared in the healthy adult gut. Moreover, different gut flora was observed between adults fed regular feed and those fed biofloc. Specifically in the biofloc-fed adult gut, several immune relevant and water-purifying bacteria were detected. The biofloc-fed adult gut flora could decompose and mineralize organic sediment, and thus be effectively utilized for integrated multitrophic aquaculture. The Venn diagram revealed that only two bacterial species were shared throughout all growth stages, and the biofloc-fed adults exhibited the highest diversity within the bacterial community.

• Food Science of Animal Resources
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• v.44 no.5
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• pp.1080-1095
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• 2024

In contemporary society, the increasing number of pet-owning households has significantly heightened interest in companion animal health, expanding the probiotics market aimed at enhancing pet well-being. Consequently, research into the gut microbiota of companion animals has gained momentum, however, ethical and societal challenges associated with experiments on intelligent and pain-sensitive animals necessitate alternative research methodologies to reduce reliance on live animal testing. To address this need, the Fermenter for Intestinal Microbiota Model (FIMM) is being investigated as an in vitro tool designed to replicate gastrointestinal conditions of living animals, offering a means to study gut microbiota while minimizing animal experimentation. The FIMM system explored interactions between intestinal microbiota and probiotics within a simulated gut environment. Two strains of commercial probiotic bacteria, Enterococcus faecium IDCC 2102 and Bifidobacterium lactis IDCC 4301, along with a newly isolated strain from domestic dogs, Lactobacillus acidophilus SLAM AK001, were introduced into the FIMM system with gut microbiota from a beagle model. Findings highlight the system's capacity to mirror and modulate the gut environment, evidenced by an increase in beneficial bacteria like Lactobacillus and Faecalibacterium and a decrease in the pathogen Clostridium. The study also verified the system's ability to facilitate accurate interactions between probiotics and commensal bacteria, demonstrated by the production of short-chain fatty acids and bacterial metabolites, including amino acids and gamma-aminobutyric acid precursors. Thus, the results advocate for FIMM as an in vitro system that authentically simulates the intestinal environment, presenting a viable alternative for examining gut microbiota and metabolites in companion animals.

• 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.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.31 no.3
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• pp.131-145
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• 2020

The microbiota-gut-brain axis, which refers to the bidirectional communication pathway between gut bacteria and the central nervous system, has a profound effect on important brain processes, from the synthesis of neurotransmitters to the modulation of complex behaviors such as sociability and anxiety. Previous studies have revealed that the gut microbiota is potentially related to not only gastrointestinal disturbances, but also social impairment and repetitive behavior-core symptoms of autism spectrum disorder (ASD). Although studies have been conducted to characterize the microbial composition in patients with ASD, the results are heterogeneous. Nevertheless, it is clear that there is a difference in the composition of the gut microbiota between ASD and typically developed individuals, and animal studies have repeatedly suggested that the gut microbiota plays an important role in ASD pathophysiology. This possibility is supported by abnormalities in metabolites produced by the gut microbiota and the association between altered immune responses and the gut microbiota observed in ASD patients. Based on these findings, various attempts have been made to use the microbiota in ASD treatment. The results reported to date suggest that microbiota-based therapies may be effective for ASD, but largescale, well-designed studies are needed to confirm this.

• Environmental Engineering Research
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• v.18 no.4
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• pp.259-265
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• 2013

This study was conducted June 2011 at Gamo Lagoon, after tsunami of March 2011, to estimate food sources and utilization. The results show that the tsunami affected the sediment properties by changing the physical environmental alterations. The fatty acids of the gut content of Nuttallia olivacea mostly comprised the same organic matter found in the sediment. Fatty acids in the tissues showed mainly diatoms, bacteria, and dinoflagellates. That is, most of the food sources (i.e., diatoms, bacteria, dinoflagellates, macroalgae, and terrestrial organic matter) probably pass through the digestive system unharmed; however, terrestrial organic matter, which is refractory to biochemical degradation, indicated a different assimilation trend between the gut content and the tissue. This result suggests that input of labile organic matter from the sediment may control selective metabolism in N. olivacea. From these results, although the physical environment of sediment characteristics by tsunami changed, the food utilization of N. olivacea suggested a better assimilation of selected components from the gut content, irrespective of physical alteration.

• Biomolecules & Therapeutics
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• v.32 no.4
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• pp.403-423
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• 2024

The human gastrointestinal (GI) tract houses a diverse microbial community, known as the gut microbiome comprising bacteria, viruses, fungi, and protozoa. The gut microbiome plays a crucial role in maintaining the body's equilibrium and has recently been discovered to influence the functioning of the central nervous system (CNS). The communication between the nervous system and the GI tract occurs through a two-way network called the gut-brain axis. The nervous system and the GI tract can modulate each other through activated neuronal cells, the immune system, and metabolites produced by the gut microbiome. Extensive research both in preclinical and clinical realms, has highlighted the complex relationship between the gut and diseases associated with the CNS, such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. This review aims to delineate receptor and target enzymes linked with gut microbiota metabolites and explore their specific roles within the brain, particularly their impact on CNS-related diseases.

• Food Science and Biotechnology
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• v.27 no.6
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• pp.1747-1754
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• 2018

The objective of this study was to evaluate probiotic effects of two Lactobacillus plantarum strains (GBL16 and 17) isolated from black raspberry. Results revealed that the number of GBL16 was gradually decreased as bile salt concentration was increased from 0.3 to 1%. However, GBL17 did not show any difference when GBL17 was applied to 1% bile salt, and it indicates that GBL17 is more tolerant to bile salt than GBL16. GBL17 exhibited higher heat resistance and adhesion ability to Caco-2 cells than GBL16. Regarding gut microbiome, no significant change in the number of total bacteria in intestines of mice after treatment with GBLs was determined. However, the combination of GBL16 and GBL17 significantly increased the number of total bacteria in intestines of mice after they were orally administered. Therefore, the results suggest that both GBL16 and 17 strains could be one of major probiotics that can improve human gut health.

• Journal of Microbiology and Biotechnology
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• v.34 no.6
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• pp.1314-1321
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• 2024

Branched-chain hydroxy acids (BCHAs), produced by lactic acid bacteria, have recently been suggested as bioactive compounds contributing to the systemic metabolism and modulation of the gut microbiome. However, the relationship between BCHAs and gut microbiome remains unclear. In this study, we investigated the effects of BCHAs on the growth of seven different families in the gut microbiota. Based on in vitro screening, both 2-hydroxyisovaleric acid (HIVA) and 2-hydroxyisocaproic acid (HICA) stimulated the growth of Lactobacillaceae and Bifidobacteriaceae, with HIVA showing a significant growth promotion. Additionally, we observed not only the growth promotion of probiotic Lactobacillaceae strains but also growth inhibition of pathogenic B. fragilis in a dose-dependent manner. The production of HIVA and HICA varied depending on the family of the gut microbiota and was relatively high in case of Lactobacillaceae and Lachnosporaceae. Furthermore, HIVA and HICA production by each strain positively correlated with their growth variation. These results demonstrated gut microbiota-derived BCHAs as active metabolites that have bacterial growth modulatory effects. We suggest that BCHAs can be utilized as active metabolites, potentially contributing to the treatment of diseases associated with gut dysbiosis.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.412-415
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• 2017

Prebiotics improve the growth or activities of specific microbial genera and species in the gut microbiota in order to confer health benefits to the host. In this study, we investigated the effect of poly-gamma-glutamate (${\gamma}-PGA$) as a prebiotic on the gut microbiota of mice and the organ distributions of ${\gamma}-PGA$ in mice. Pyrosequencing analysis for 16S rRNA genes of bacteria indicated that oral administration of ${\gamma}-PGA$ increased the abundance of Lactobacillales while reducing the abundance of Clostridiales in murine guts. It is suggested that oral administration of ${\gamma}-PGA$ can be helpful for modulating the gut microbiota as a prebiotic.