• Journal of Animal Science and Technology
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• 제64권4호
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• pp.671-695
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• 2022

The gastrointestinal tract is a complex ecosystem that contains a large number of microorganisms with different metabolic capacities. Modulation of the gut microbiome can improve the growth and promote health in pigs. Crosstalk between the host, diet, and the gut microbiome can influence the health of the host, potentially through the production of several metabolites with various functions. Short-chain and branched-chain fatty acids, secondary bile acids, polyamines, indoles, and phenolic compounds are metabolites produced by the gut microbiome. The gut microbiome can also produce neurotransmitters (such as γ-aminobutyric acid, catecholamines, and serotonin), their precursors, and vitamins. Several studies in pigs have demonstrated the importance of the gut microbiome and its metabolites in improving growth performance and feed efficiency, alleviating stress, and providing protection from pathogens. The use of probiotics is one of the strategies employed to target the gut microbiome of pigs. Promising results have been published on the use of probiotics in optimizing pig production. This review focuses on the role of gut microbiome-derived metabolites in the performance of pigs and the effects of probiotics on altering the levels of these metabolites.

• Biomolecules & Therapeutics
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• 제32권4호
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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.

• Korean Circulation Journal
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• 제53권8호
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• pp.499-518
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• 2023

Cardiovascular diseases (CVDs), including coronary artery disease, stroke, heart failure, and hypertension, are the global leading causes of death, accounting for more than 30% of deaths worldwide. Although the risk factors of CVDs have been well understood and various treatment and preventive measures have been established, the mortality rate and the financial burden of CVDs are expected to grow exponentially over time due to the changes in lifestyles and increasing life expectancies of the present generation. Recent advancements in metagenomics and metabolomics analysis have identified gut microbiome and its associated metabolites as potential risk factors for CVDs, suggesting the possibility of developing more effective novel therapeutic strategies against CVD. In addition, increasing evidence has demonstrated the alterations in the ratio of Firmicutes to Bacteroidetes and the imbalance of microbial-dependent metabolites, including short-chain fatty acids and trimethylamine N-oxide, play a crucial role in the pathogenesis of CVD. However, the exact mechanism of action remains undefined to this day. In this review, we focus on the compositional changes in the gut microbiome and its related metabolites in various CVDs. Moreover, the potential treatment and preventive strategies targeting the gut microbiome and its metabolites are discussed.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제19권4호
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• pp.221-228
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• 2016

The gastrointestinal exposome represents the integration of all xenobiotic components and host-derived endogenous components affecting the host health, disease progression and ultimately clinical outcomes during the lifespan. The human gut microbiome as a dynamic exposome of commensalism continuously interacts with other exogenous exposome as well as host sentineling components including the immune and neuroendocrine circuit. The composition and diversity of the microbiome are established on the basis of the luminal environment (physical, chemical and biological exposome) and host surveillance at each part of the gastrointestinal lining. Whereas the chemical exposome derived from nutrients and other xenobiotics can influence the dynamics of microbiome community (the stability, diversity, or resilience), the microbiomes reciprocally alter the bioavailability and activities of the chemical exposome in the mucosa. In particular, xenobiotic metabolites by the gut microbial enzymes can be either beneficial or detrimental to the host health although xenobiotics can alter the composition and diversity of the gut microbiome. The integration of the mucosal crosstalk in the exposome determines the fate of microbiome community and host response to the etiologic factors of disease. Therefore, the network between microbiome and other mucosal exposome would provide new insights into the clinical intervention against the mucosal or systemic disorders via regulation of the gut-associated immunological, metabolic, or neuroendocrine system.

• 대한한의학방제학회지
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• 제31권4호
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• pp.341-360
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• 2023

Background : To investigate the effect of Hwanggeumjackyak-tang (HJT) on Dextran sulfate sodium (DSS) induced ulcerative colitis. Methods : The experimental animals were divided into three groups; group 1, normal group(Normal); group 2, DSS-induced colitis and untreated group(UT+DSS); group 3, DSS-induced colitis and HJT 200 mg-treated group(HJT200+DSS). We evaluated cytotoxicity after HJT administration and confirmed the anti-inflammatory effect by histological changes in the intestine and genetic analysis of mucosal cells after HJT administration for each group. In addition, microbiological weapons and metabolites in faeces were examined, and the correlation between gut microbiome and metabolites was also investigated. Result : HJT was not observed to be cytotoxic, even at relatively high concentrations, and was effective in protecting the barrier and preventing intestinal inflammation by suppressing the increase in mucus secretion and the expression of inflammatory factors in mucosal cells. HJT treatment affected the increase in the amount and diversity of the gut microbiome in faeces and the increase in metabolites thought to be involved in alleviating inflammation in the gut. Conclusion : This study demonstrates the therapeutic potential of HJT in ulcerative colitis. Further studies should be carried out to confirm our findings.

• Journal of Microbiology and Biotechnology
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• 제34권6호
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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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• 제32권5호
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• pp.612-620
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• 2022

Recent studies have revealed that probiotics and their metabolites are present under various conditions; however, the role of probiotic metabolites (i.e., postbiotics in pathological states) is controversial. Natural killer (NK) cells play a key role in innate and adaptive immunity. In this study, we examined NK cell activation influenced by a postbiotics mixture in response to gut microbiome modulation in stress-induced mice. In vivo activation of NK cells increased in the postbiotics mixture treatment group in accordance with Th1/Th2 expression level. Meanwhile, the Red Ginseng treatment group, a reference group, showed very little expression of NK cell activation. Moreover, the postbiotics mixture treatment group in particular changed the gut microbiome composition. Although the exact role of the postbiotics mixture in regulating the immune system of stress-induced mice remains unclear, the postbiotics mixture-induced NK cell activation might have affected gut microbiome modulation.

• Journal of Microbiology and Biotechnology
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• 제31권2호
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• pp.240-249
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• 2021

Phenotypic plasticity is a rapid response mechanism that enables organisms to acclimate and survive in changing environments. The Chinese mitten crab (Eriocheir sinensis) survives and thrives in different and even introduced habitats, thereby indicating its high phenotypic plasticity. However, the underpinnings of the high plasticity of E. sinensis have not been comprehensively investigated. In this study, we conducted an integrated gut microbiome and muscle metabolome analysis on E. sinensis collected from three different environments, namely, an artificial pond, Yangcheng Lake, and Yangtze River, to uncover the mechanism of its high phenotypic plasticity. Our study presents three divergent gut microbiotas and muscle metabolic profiles that corresponded to the three environments. The composition and diversity of the core gut microbiota (Proteobacteria, Bacteroidetes, Tenericutes, and Firmicutes) varied among the different environments while the metabolites associated with amino acids, fatty acids, and terpene compounds displayed significantly different concentration levels. The results revealed that the gut microbiome community and muscle metabolome were significantly affected by the habitat environments. Our findings indicate the high phenotypic plasticity in terms of gut microbiome and muscle metabolome of E. sinensis when it faces environmental changes, which would also facilitate its acclimation and adaptation to diverse and even introduced environments.

• BMB Reports
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• 제56권1호
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• pp.15-23
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• 2023

After birth, animals are colonized by a diverse community of microorganisms. The digestive tract is known to contain the largest number of microbiome in the body. With emergence of the gut-brain axis, the importance of gut microbiome and its metabolites in host health has been extensively studied in recent years. The establishment of organoid culture systems has contributed to studying intestinal pathophysiology by replacing current limited models. Owing to their architectural and functional complexity similar to a real organ, co-culture of intestinal organoids with gut microbiome can provide mechanistic insights into the detrimental role of pathobiont and the homeostatic function of commensal symbiont. Here organoid-based bacterial co-culture techniques for modeling host-microbe interactions are reviewed. This review also summarizes representative studies that explore impact of enteric microorganisms on intestinal organoids to provide a better understanding of host-microbe interaction in the context of homeostasis and disease.

• Journal of Microbiology and Biotechnology
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• 제34권4호
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• pp.747-756
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• 2024

Chronic gut inflammation promotes the development of metabolic diseases such as obesity. There is growing evidence which suggests that dysbiosis in gut microbiota and metabolites disrupt the integrity of the intestinal barrier and significantly impact the level of inflammation in various tissues, including the liver and adipose tissues. Moreover, dietary sources are connected to the development of leaky gut syndrome through their interaction with the gut microbiota. This review examines the effects of these factors on intestinal microorganisms and the communication pathways between the gut-liver and gut-brain axis. The consumption of diets rich in fats and carbohydrates has been found to weaken the adherence of tight junction proteins in the gastrointestinal tract. Consequently, this allows endotoxins, such as lipopolysaccharides produced by detrimental bacteria, to permeate through portal veins, leading to metabolic endotoxemia and alterations in the gut microbiome composition with reduced production of metabolites, such as short-chain fatty acids. However, the precise correlation between gut microbiota and alternative sweeteners remains uncertain, necessitating further investigation. This study highlights the significance of exploring the impact of diet on gut microbiota and the underlying mechanisms in the gut-liver and gut-brain axis. Nevertheless, limited research on the gut-liver axis poses challenges in comprehending the intricate connections between diet and the gut-brain axis. This underscores the need for comprehensive studies to elucidate the intricate gut-brain mechanisms underlying intestinal health and microbiota.