• Biomedical Science Letters
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• v.23 no.3
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• pp.166-174
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• 2017

The bacterial cells located within the gastrointestinal tract (GIT) outnumber the host's cells by a factor of ten. These human digestive-tract microbes are referred to as the gut microbiota. During the last ten years, our understanding of gut microbiota composition and its relation with intra- and extra-intestinal diseases including risk factors of cardiovascular diseases (CVD) such as atherosclerosis and metabolic syndrome, have greatly increased. A question which frequently arises in the research community is whether one can modulate the gut microbial environment to 'control' risk factors in CVD. In this review, we summarized promising intervention methods, based on our current knowledge of intestinal microbiota in modulating CVD. Furthermore, we explore how gut microbiota can be therapeutically exploited by targeting their metabolic program to control pathologic factors of CVD.

• Journal of Microbiology and Biotechnology
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• v.33 no.10
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• pp.1317-1328
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• 2023

Green tea (GT) polyphenols undergo extensive metabolism within gastrointestinal tract (GIT), where their derivatives compounds potentially modulate the gut microbiome. This biotransformation process involves a cascade of exclusive gut microbial enzymes which chemically modify the GT polyphenols influencing both their bioactivity and bioavailability in host. Herein, we examined the in vitro interactions between 37 different human gut microbiota and the GT polyphenols. UHPLC-LTQ-Orbitrap-MS/MS analysis of the culture broth extracts unravel that genera Adlercreutzia, Eggerthella and Lactiplantibacillus plantarum KACC11451 promoted C-ring opening reaction in GT catechins. In addition, L. plantarum also hydrolyzed catechin galloyl esters to produce gallic acid and pyrogallol, and also converted flavonoid glycosides to their aglycone derivatives. Biotransformation of GT polyphenols into derivative compounds enhanced their antioxidant bioactivities in culture broth extracts. Considering the effects of GT polyphenols on specific growth rates of gut bacteria, we noted that GT polyphenols and their derivate compounds inhibited most species in phylum Actinobacteria, Bacteroides, and Firmicutes except genus Lactobacillus. The present study delineates the likely mechanisms involved in the metabolism and bioavailability of GT polyphenols upon exposure to gut microbiota. Further, widening this workflow to understand the metabolism of various other dietary polyphenols can unravel their biotransformation mechanisms and associated functions in human GIT.

• Korean Journal of Microbiology
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• v.50 no.4
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• pp.265-274
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• 2014

Gut microbiota is a group of microorganisms that resides in the intestine and serves many important functions in human health. Using 16S ribosomal RNA sequencing analysis, a wide variety of bacteria in human gastrointestinal tract has been identified along with intriguing findings that there is a different bacterial composition among individuals. Fecal microbiota transplantation (FMT) is a procedure of stool transplantation from healthy donors to patients suffering from various diseases. Specifically, FMT is able to alter the composition of gut microbiota of recipients and therefore could be an effective treatment for the patients with gastrointestinal diseases including recurrent Clostridium difficile infection, inflammatory bowel disease, and irritable bowel syndrome. Here we review a list of human diseases related to gut microbiota disturbance and the case studies of FMT. We also summarize medicines and diagnostic tools that are under development. Therefore, gut microbiota can be a next generation's biotherapy for promotion of health and treatment of chronic diseases.

• 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.

• Korean Journal of Exercise Nutrition
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• v.25 no.2
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• pp.1-7
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• 2021

[Purpose] Recent studies have shown that COVID-19 is often associated with altered gut microbiota composition and reflects disease severity. Furthermore, various reports suggest that the interaction between COVID-19 and host-microbiota homeostasis is mediated through the modulation of microRNAs (miRNAs). Thus, in this review, we aim to summarize the association between human microbiota and miRNAs in COVID-19 pathogenesis. [Methods] We searched for the existing literature using the keywords such "COVID-19 or microbiota," "microbiota or microRNA," and "COVID-19 or probiotics" in PubMed until March 31, 2021. Subsequently, we thoroughly reviewed the articles related to microbiota and miRNAs in COVID-19 to generate a comprehensive picture depicting the association between human microbiota and microRNAs in the pathogenesis of COVID-19. [Results] There exists strong experimental evidence suggesting that the composition and diversity of human microbiota are altered in COVID-19 patients, implicating a bidirectional association between the respiratory and gastrointestinal tracts. In addition, SARS-CoV-2 encoded miRNAs and host cellular microRNAs modulated by human microbiota can interfere with viral replication and regulate host gene expression involved in the initiation and progression of COVID-19. These findings suggest that the manipulation of human microbiota with probiotics may play a significant role against SARS-CoV-2 infection by enhancing the host immune system and lowering the inflammatory status. [Conclusion] The human microbiota-miRNA axis can be used as a therapeutic approach for COVID-19. Hence, further studies are needed to investigate the exact molecular mechanisms underlying the regulation of miRNA expression in human microbiota and how these miRNA profiles mediate viral infection through host-microbe interactions.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.126-126
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• 2018

Many of researches have revealed that human intestinal microbiota is related to health. Several diseases like obesity, diabetes, and hypertension are affected by the microbiota directly and indirectly. So, interventions with food and drug have been tried to change a composition of the microbiota to better condition. However, few natural medicines have elucidated to date. To understand an influence on microbiota by plant materials including Glycyrrhizae Radix, the extract of medicines were administered to mice and the feces were collected before and after the administration. The feces were analyzed by terminal restriction fragment length polymorphism (T-RFLP). The changes in composition of mice gut microbiota were detected and analyzed. The data could be utilized to further study about biological activities of the plant medicines.

• Journal of Animal Science and Technology
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• v.62 no.2
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• pp.239-246
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• 2020

Microorganism residing in the gut has been known to have important roles in the animal body. Microbes and host microenvironment are highly related with host's health including energy metabolism and immune system. Moreover, it reported that gut microbiome is correlated with diseases like obesity in human and dogs. There have been many studies to identify and characterize microbes and their genes in human body. However, there was little information of microbiome in companion animals. Here, we investigated microbiota communities in feaces from twenty - four Beagles (aged 2 years old) and analyzed the taxonomy profile using metagenomics to study the difference among gut microbiome based on body condition score (BCS). gDNA was isolated from feaces, sequenced and clustered. Taxonomy profiling was performed based on the NCBI database. BCS was evaluated once a week according to the description provided by World Small Animal Veterinary Association. Firmicutes phylum was the most abundant followed by Bacteroidetes, Fusobacteria, Proteobacteria and Actinobacteria. That main microbiota in gut were differently distributed based on the BCS. Fusobacteria has been known to be associated with colon cancer in human. Interestingly, Fusobacteria was in the third level from the top in healthy dog's gut microbiome. In addition, Fusobacteria was especially higher in overweight dogs which had 6 scales of BCS. Species Fusobacterium perfoetens was also more abundant when dogs were in BCS 6. It implied that F. perfoetens would be positively related with overweight in dogs. These finding would contribute to further studies of gut microbiome and their functions to improve dog's diets and health condition.

• Journal of Applied Biological Chemistry
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• v.63 no.1
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• pp.83-87
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• 2020

Fermented foods have been recognized as functional foods that provide health benefits, including the modulation of intestinal microbiota. Therefore, the aim of the present study was to examine the effects of coffee beans fermented with Lactobacillus plantarum and Bacillus amyloliquefaciens on healthy human gut microbiota. Fermentation increased the content of beneficial substances (i.e., flavonoids and polyphenols). The consumption of fermented coffee increased the occurrence of beneficial microorganisms such as fiber degraders and short-chain fatty acid producers, although no significant microbiota shifts were observed after the coffee consumption. The analysis of metabolic activities also showed no difference after the coffee consumption. Our study demonstrates that the consumption of the fermented coffee may increase some beneficial bacterial while remaining the gut microbiota and its activities.

• Journal of Applied Biological Chemistry
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• v.64 no.1
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• pp.75-81
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• 2021

Recent gut microbiota studies have revealed the important roles of gut microbiota for our health. Increasing numbers of health functional foods have been developed every year. Development of functional food often includes ex- and in-vivo experiment to verify the beneficial effects of the functional food. To investigate effects of functional food on gut microbiota, animal models were often conducted. Beneficial effects of food can be evaluated based on how gut microbiota was shifted by food, which results in either increase in beneficial bacteria, decrease in potentially pathogenic bacteria or both. As animal experiments are generally time-consuming and laborious, we investigate how well in-vitro investigation of fecal microbiota may reflect dietary health benefits. Here, we tested 15 kinds of diets using two human subjects' fecal materials. Our results showed varying gut microbiota shifts according to diets, which suggested generally known beneficial diets (i.e. Kimchi, Chunggukjang) increased Lactobacillus and Bifidobacterium. Therefore, we suggest that in vitro fecal microbiota analysis could be used to evaluate beneficial effects of diets. Moreover, this method may be ideal to establish personalized diet.

• Microbiology and Biotechnology Letters
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• v.46 no.3
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• pp.277-287
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• 2018

Current reports suggest that obesity is a serious global health issue. Emerging evidence has predicted strong links between obesity and the human gut microbiota. However, only a few such studies have been conducted in Asia, and the gut microbiota of lean and obese adult Asians remains largely unexplored. Here, we investigated the potential relationship between gut microbiota, body massindex (BMI), and metabolic parameters in adults from Thailand, where obesity is increasing rapidly. Fecal and blood samples were collected from 42 volunteers who were allocated into lean, overweight, and obese groups. The fecal microbiota was examined by quantitative PCR analysis. Bacteroidetes, Firmicutes, and Staphylococcus spp. and methanogens were most abundant in lean volunteers. Overweight volunteers majorly harbored Christensenella minuta and Akkermansia muciniphila, ${\gamma}-Proteobacteria$, and bacteria belonging to the genus Ruminococcus. Methanogens and bacteria belonging to the phylum Bacteroidetes were negatively correlated with adiposity markers (BMI and waist circumference), but positive correlated with high-density lipoprotein, suggesting that they can be used as leanness markers. While some of our results agree with those of previous reports, results regarding the contributions of specific taxa to obesity were inconsistent. This is the first study to report the adult gut microbiota in Southeast Asian populations using molecular techniques and biochemical markers and provides a foundation for future studies in this field.