• 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.

• Journal of Dairy Science and Biotechnology
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• v.37 no.1
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• pp.15-26
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• 2019

A common belief is that human milk is sterile. However, the development of culture-independent molecular methods, especially Next Generation Sequencing, has revealed that human milk harbors diverse and rich bacterial communities. Although studies aimed at characterizing the microbiota of human milk have produced different findings, Staphylococcus and Streptococcus are presumed to be normal members of the microbiota. Factors that influence variation in the microbiota are unclear; however, the postpartum time, route of delivery, maternal obesity, and health status may be influential. The origin of the microbiota is a hotly debated topic. Human milk bacteria are thought to be introduced through bacterial exposure of the mammary duct during breast feeding and/or the entero-mammary pathway from the maternal gastrointestinal tract. Although the exact mechanism related to the entero-mammary pathway is unknown, it is presumed that bacteria penetrate the intestinal epithelium and then migrate to the mammary gland, dendritic cells, and macrophages. In this review, various relevant studies are introduced.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.16 no.2
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• pp.71-79
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• 2013

The human-associated microbiota is diverse, varies between individuals and body sites, and is important in human health. Microbes in human body play an essential role in immunity, health, and disease. The human microbiome has been studies using the advances of next-generation sequencing and its metagenomic applications. This has allowed investigation of the microbial composition in the human body, and identification of the functional genes expressed by this microbial community. The gut microbes have been found to be the most diverse and constitute the densest cell number in the human microbiota; thus, it has been studied more than other sites. Early results have indicated that the imbalances in gut microbiota are related to numerous disorders, such as inflammatory bowel disease, colorectal cancer, diabetes, and atopy. Clinical therapy involving modulating of the microbiota, such as fecal transplantation, has been applied, and its effects investigated in some diseases. Human microbiome studies form part of human genome projects, and understanding gleaned from studies increase the possibility of various applications including personalized medicine.

• BMB Reports
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• v.45 no.8
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• pp.433-441
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• 2012

Human milk, which nourishes the early infants, is a source of bioactive components for the infant growth, development and commensal formulation as well. Human milk oligosaccharide is a group of complex and diverse glycans that is apparently not absorbed in human gastrointestinal tract. Although most mammalian milk contains oligosaccharides, oligosaccharides in human milk exhibit unique features in terms of their types, amounts, sizes, and functionalities. In addition to the prevention of infectious bacteria and the development of early immune system, human milk oligosaccharides are able to facilitate the healthy intestinal microbiota. Bifidobacterial intestinal microbiota appears to be established by the unilateral interaction between milk oligosaccharides, human intestinal activity and commensals. Digestibility, membrane transportation and catabolic activity by bacteria and intestinal epithelial cells, all of which are linked to the structural of human milk oligosaccharides, are crucial in determining intestinal microbiota.

• The Journal of Pediatrics of Korean Medicine
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• v.33 no.1
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• pp.34-45
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• 2019

Objectives The purpose of this study is to highlight recent gut-microbiota studies and to encourage gut-microbiota-related researches in Pediatric science of Korean Medicine. Methods We searched gut microbiota related studies and patents via the PubMed database of the US National Institutes of Health (NIH) and the PatentScope database of the UN World Intellectual Property Organization (WIPO) to see current trends of gut microbiota studies. Results All searched research and review articles in gut-microbiota studies were analyzed and presented as two charts, showing the recent trends of gut microbiota research. We summarized and discussed the significance of the selected fifty-six articles. Also, we listed reported gut-microbiota-derived small metabolites, impacting on human health and diseases. Conclusions This study emphasizes the critical roles of gut-microbiota and their-derived small metabolites in the human physiology and pathology. We know and agree that many natural compounds in Korean Medicine could be converted into small metabolites by gut microbiota in our body. Thus, it is important to encourage physicians and researchers of gut microbiota in the arena of Pediatric Korean Medicine. We believe that researchers will find a lot of unknown metabolites produced by gut microbiota from natural compounds in Korean Medicine.

• Bulletin of Food Technology
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• v.25 no.2
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• pp.134-141
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• 2012

• Journal of Korean Medicine for Obesity Research
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• v.9 no.1
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• pp.1-14
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• 2009

Complex microbial communities play an important role in the human health and co-evolved with human in the form of symbiosis. Many literatures provide new evidences that the increased prevalence of obesity cannot be attributed solely to changes in the human genome, nutritional habits, or reduction of physical activity in our daily lives. The intestinal flora was recently proposed as an environmental factor responsible for the control of body weight and energy metabolism. A number of studies suggest that the modulation of gut microbiota affects host metabolism and has an impact on energy storage and demonstrated a role for the gut microbiota in weight gain, fat increase, and insulin resistance. Variations in microbiota composition are found in obese humans and mice and the microbiota from an obese mouse confers an obese phenotype when transferred to an axenic mouse. As well, the gut microbial flora plays a role in converting nutrients into calories. Specific strategies for modifying gut microbiota may be a useful means to treat or prevent obesity. Dietary modulations of gut microbiota with a view to increasing bifidobacteria have demonstrated to reduce endotoxemia and improve metabolic diseases such as obesity. The fermentation of medicinal herbs is intended to exert a favorable influence on digestability, bioavailability and pharmacological activity of herbal extract. Therefore we also expect that the fermented herbal extracts may open up a new area to treat obesity through modulating gut microbiota.

• 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.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.

• Biomolecules & Therapeutics
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• v.19 no.2
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• pp.155-173
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• 2011

Humans have and hold 100 trillion intestinal bacteria that are essential for health. For millions of years human-microorganisms interaction has co-evolved, and maintained close symbiotic relationship. Gut bacteria contributes to human health and metabolism, and humans provides the optimum nutrition-rich environment for bacteria. What is the mechanism of the host distinguishing the intestinal bacteria as its cohabiting partner and what kind of benefits does the gut microbiota provide the human are the fundamental questions to be asked and solved in order to make human life a higher quality. This review explains the physiological relationship and mutualism between the host and gut microorganism, and highlights the potential therapeutic approach for treating diseases, maintaining and improving health based on these correlations.