• IMMUNE NETWORK
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• 제21권3호
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• pp.20.1-20.18
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• 2021

The gut is an important organ with digestive and immune regulatory function which consistently harbors microbiome ecosystem. The gut microbiome cooperates with the host to regulate the development and function of the immune, metabolic, and nervous systems. It can influence disease processes in the gut as well as extra-intestinal organs, including the brain. The gut closely connects with the central nervous system through dynamic bidirectional communication along the gut-brain axis. The connection between gut environment and brain may affect host mood and behaviors. Disruptions in microbial communities have been implicated in several neurological disorders. A link between the gut microbiota and the brain has long been described, but recent studies have started to reveal the underlying mechanism of the impact of the gut microbiota and gut barrier integrity on the brain and behavior. Here, we summarized the gut barrier environment and the 4 main gut-brain axis pathways. We focused on the important function of gut barrier on neurological diseases such as stress responses and ischemic stroke. Finally, we described the impact of representative environmental sensors generated by gut bacteria on acute neurological disease via the gut-brain axis.

• Nutrition Research and Practice
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• 제15권4호
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• pp.411-430
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• 2021

Irritable bowel syndrome (IBS) is a frequently diagnosed gastrointestinal (GI) disorder characterized by recurrent abdominal pain, bloating, and changes in the stool form or frequency without any structural changes and overt inflammation. It is not a life-threatening condition but causes a considerable level of discomfort and distress. Among the many pathophysiologic factors, such as altered GI motility, visceral hypersensitivity, and low-grade mucosal inflammation, as well as other immunologic, psychologic, and genetic factors, gut microbiota imbalance (dysbiosis), which is frequently found in IBS, has been highlighted as an etiology of IBS. Dysbiosis may affect gut mucosal homeostasis, immune function, metabolic regulation, and even visceral motor function. As diet is shown to play a fundamental role in the gut microbiota profile, this review discusses the influence of diet on IBS occurring through the modulation of gut microbiota. Based on previous studies, it appears that dietary modulation of the gut microbiota may be effective for the alleviation of IBS symptoms and, also an effective IBS management strategy based on the underlying mechanism; especially because, IBS currently has no specific treatment owing to its uncertain etiology.

• 동의신경정신과학회지
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• 제34권3호
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• pp.275-305
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• 2023

Objectives: This study aimed to review clinical and experimental studies using Korean traditional herbal medicine for dementia on the improvement of cognitive function and changes in gut microbiota. Methods: We searched 12 databases for clinical and experimental studies on the effect of Korean traditional herbal medicine treatment for dementia on changes in gut microbiota. Sample sizes, dementia types, diagnosis criteria, interventions, outcomes, and results, including changes in gut microbiota, were extracted from the included clinical studies and analyzed. Subjects, interventions, outcomes, and results, including gut microbiota changes, were extracted from the included experimental studies and analyzed. Results: A total of 22 studies were selected, and most of them were experimental studies. Improvement in cognitive function and changes in gut microbiota were reported in all studies. The most frequently used herbal material was Poria cocos, and the most frequently used prescription was Danggwijagyak-san and Chilseong-hwan. Lactobacillus, Firmicutes, Bacteroidetes, and Proteobacteria were frequently assessed gut microbiota. Conclusions: These results suggest the treatment potential of Korean traditional herbal medicine for dementia by regulating gut microbiota. However, there were discrepancies related to changes in gut microbiota among studies. Therefore, further studies are needed to clarify the effect and mechanism of Korean traditional herbal medicine for dementia on gut microbiota.

• 한국축산식품학회지
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• 제43권5호
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• pp.723-750
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• 2023

The gut microbiome is critical in human health, and various dietary factors influence its composition and function. Among these factors, animal products, such as meat, dairy, and eggs, represent crucial sources of essential nutrients for the gut microbiome. However, the correlation and characteristics of livestock consumption with the gut microbiome remain poorly understood. This review aimed to delineate the distinct effects of meat, dairy, and egg products on gut microbiome composition and function. Based on the previous reports, the impact of red meat, white meat, and processed meat consumption on the gut microbiome differs from that of milk, yogurt, cheese, or egg products. In particular, we have focused on animal-originated proteins, a significant nutrient in each livestock product, and revealed that the major proteins in each food elicit diverse effects on the gut microbiome. Collectively, this review highlights the need for further insights into the interactions and mechanisms underlying the impact of animal products on the gut microbiome. A deeper understanding of these interactions would be beneficial in elucidating the development of dietary interventions to prevent and treat diseases linked to the gut microbiome.

• Journal of Ginseng Research
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• 제45권2호
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• pp.334-343
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• 2021

Background: Gut microbiota mainly function in the biotransformation of primary ginsenosides into bioactive metabolites. Herein, we investigated the effects of three prebiotic fibers by targeting gut microbiota on the metabolism of ginsenoside Rb1 in vivo. Methods: Sprague Dawley rats were administered with ginsenoside Rb1 after a two-week prebiotic intervention of fructooligosaccharide, galactooligosaccharide, and fibersol-2, respectively. Pharmacokinetic analysis of ginsenoside Rb1 and its metabolites was performed, whilst the microbial composition and metabolic function of gut microbiota were examined by 16S rRNA gene amplicon and metagenomic shotgun sequencing. Results: The results showed that peak plasma concentration and area under concentration time curve of ginsenoside Rb1 and its intermediate metabolites, ginsenoside Rd, F2, and compound K (CK), in the prebiotic intervention groups were increased at various degrees compared with those in the control group. Gut microbiota dramatically responded to the prebiotic treatment at both taxonomical and functional levels. The abundance of Prevotella, which possesses potential function to hydrolyze ginsenoside Rb1 into CK, was significantly elevated in the three prebiotic groups (P < 0.05). The gut metagenomic analysis also revealed the functional gene enrichment for terpenoid/polyketide metabolism, glycolysis, gluconeogenesis, propanoate metabolism, etc. Conclusion: These findings imply that prebiotics may selectively promote the proliferation of certain bacterial stains with glycoside hydrolysis capacity, thereby, subsequently improving the biotransformation and bioavailability of primary ginsenosides in vivo.

• 대한수학회지
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• 제49권4호
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• pp.795-804
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• 2012

In this paper, we obtain two general laws of precise asymptotics for sums of i.i.d random variables, which contain general weighted functions and boundary functions and also clearly show the relationship between the weighted functions and the boundary functions. As corollaries, we obtain Theorem 2 of Gut and Spataru [A. Gut and A. Sp$\check{a}$taru, Precise asymptotics in the law of the iterated logarithm, Ann. Probab. 28 (2000), no. 4, 1870-1883] and Theorem 3 of Gut and Sp$\check{a}$taru [A. Gut and A. Sp$\check{a}$taru, Precise asymptotics in the Baum-Katz and Davids laws of large numbers, J. Math. Anal. Appl. 248 (2000), 233-246].

• 식품과학과 산업
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• 제52권3호
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• pp.208-219
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• 2019

Probiotics are very closely related to gut microbiome and recognized as beneficial microorganisms for our health. They have various biological effects such as inhibition of pathogenic bacteria, activation of beneficial bacteria, prevention of diarrhea and constipation, enhanced immune activity etc. Prebiotics, non-digestible carbohydrates such as galactooligosaccharide and fructooligosaccharide, are utilized by beneficial gut bacteria such as bifidobacteria and lactobacilli, resulting in production of short chain fatty acids which inhibit pathogenic bacteria in the gut and function for human health. Synbiotics are introduced for synergistic effects when probiotics are combined with prebiotics and now commercially available. At the moment many functional ingredients are developed and commercialized. Probiotics, prebiotics, and synbiotics might be hot items in the functional food market and the values will increase according to the results of human gut microbiome researches. To meet the situation, systematic and scientific studies as well as marketing effects should be accompanied.

• IMMUNE NETWORK
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• 제23권1호
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• pp.6.1-6.24
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• 2023

Intestinal microorganisms interact with various immune cells and are involved in gut homeostasis and immune regulation. Although many studies have discussed the roles of the microorganisms themselves, interest in the effector function of their metabolites is increasing. The metabolic processes of these molecules provide important clues to the existence and function of gut microbes. The interrelationship between metabolites and T lymphocytes in particular plays a significant role in adaptive immune functions. Our current review focuses on 3 groups of metabolites: short-chain fatty acids, bile acids metabolites, and polyamines. We collated the findings of several studies on the transformation and production of these metabolites by gut microbes and explained their immunological roles. Specifically, we summarized the reports on changes in mucosal immune homeostasis represented by the Tregs and Th17 cells balance. The relationship between specific metabolites and diseases was also analyzed through latest studies. Thus, this review highlights microbial metabolites as the hidden treasure having potential diagnostic markers and therapeutic targets through a comprehensive understanding of the gut-immune interaction.

• Journal of Dairy Science and Biotechnology
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• 제37권1호
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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.

• Journal of Applied Biological Chemistry
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• 제65권1호
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• pp.63-74
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• 2022

Microbial dysbiosis in the gut is associated with human diseases, and variations in mucus alter gut microbiota. Therefore, we explored the effects of mucin on the gut microbiota using a community of 19 synthetic gut microbial species. Cultivation of these species in modified Gifu anaerobic medium (GAM) supplemented with mucin before synthetic community assembly facilitated substantial growth of the Bacteroides, Akkermansia, and Clostridium genera. The results of 16S rRNA microbial relative abundance profiling revealed more of the beneficial microbes Collinsella, Bifidobacterium, Ruminococcus, and Lactobacillus. This increased acetate levels in the community cultivated with, rather than without (control), mucin. We identified differences in predicted cell function and metabolism between microbes cultivated in GAM with and without mucin. Mucin not only changed the composition of the gut microbial community, but also modulated metabolic functions, indicating that it could help to modulate microbial changes associated with human diseases.