• Korean Journal of Microbiology
• /
• v.55 no.3
• /
• pp.220-225
• /
• 2019

Studies based on microbial community analyses have increased in the recent decade since the development of next generation sequencing technology. Associations of gut microbiota with host's health are one of the major outcomes of microbial ecology filed. The major approach for microbial community analysis includes the sequencing of variable regions of 16S rRNA genes, which does not provide the information of bacterial activities. Here, we conducted RNA-based microbial community analysis and compared results obtained from DNA- and its cDNA-based microbial community analyses. Our results indicated that these two approaches differed in the ratio of Firmicutes and Bacteroidetes, known as an obesity indicator, as well as abundance of some key bacteria in gut metabolisms such as butyrate producers and probiotics strains. Therefore, cDNA-based microbial community may provide different insights regarding roles of gut microbiota compared to the previous studies where DNA-based microbial community analyses were performed.

• Journal of Life Science
• /
• v.28 no.11
• /
• pp.1386-1395
• /
• 2018

Over recent years, it has become evident that the central nervous system bidirectionally interacts with the gastrointestinal tract along the gut-brain axis. A series of preclinical studies indicate that the gut microbiota can modulate central nervous system function through a multitude of physiological functions. Polyphenols are ubiquitous plant chemicals included in foods such as fruits, vegetables, tea, coffee and wine, and their consumption is directly responsible for beneficial health effects due to antioxidant, anti-inflammatory, antimicrobial, immunomodulatory, anticancer, vasodilating, and prebiotic-like effects. There is increasing evidence that dietary polyphenol can contribute to beneficial effects in neuronal protection acting against oxidative stress and inflammatory injury as well as in cognitive functions. In this paper, we overview the neuroprotective role of dietary polyphenols especially focusing on the neuroinflammation and neurovascular function by interaction with the gut microbiome. Polyphenol metabolites could directly act as neurotransmitters crossing the blood-brain barrier and modulating the cerebrovascular system or indirectly modulating gut microbiota. In addition, evidence suggests that dietary polyphenols are effective in preventing and managing neurological disorders, such as age-related cognitive decline and neurodegeneration, through a multitude of physiological functions. Dietary polyphenols are increasingly envisaged as a potential nutraceuticals in the prevention and treatment of neurological disorders, because they possess the ability to reduce neuroinflammation, to improve memory and cognitive function and to modulate the gut microbiota.

• Korean Journal of Veterinary Research
• /
• v.55 no.3
• /
• pp.205-208
• /
• 2015

Ten dogs were enrolled in this study: two healthy dogs, two obese dogs without other medical issues and six obese dogs with underlying diseases including pemphigus, chronic active hepatitis, hyperadrenocorticism, narcolepsy, otitis media and heartworm infection. Pyrosequencing of the 16S rRNA gene to explore the gut bacterial diversity revealed that distal gut bacterial communities of samples from patients with pemphigus, otitis media and narcolepsy consisted primarily of Firmicutes, while the major phylum of the distal gut bacterial communities in patients with chronic active hepatitis and hyperadrenocorticism was Fusobacteria. Proteobacteria were the dominant phylum in heartworm infected obese patients.

• Asian-Australasian Journal of Animal Sciences
• /
• v.28 no.9
• /
• pp.1217-1225
• /
• 2015

Chicken is a major food source for humans, hence it is important to understand the mechanisms involved in nutrient absorption in chicken. In the gastrointestinal tract (GIT), the microbiota plays a central role in enhancing nutrient absorption and strengthening the immune system, thereby affecting both growth and health of chicken. There is little information on the diversity and functions of chicken GIT microbiota, its impact on the host, and the interactions between the microbiota and host. Here, we review the recent metagenomic strategies to analyze the chicken GIT microbiota composition and its functions related to improving metabolism and health. We summarize methodology of metagenomics in order to obtain bacterial taxonomy and functional inferences of the GIT microbiota and suggest a set of indicator genes for monitoring and manipulating the microbiota to promote host health in future.

• Journal of Ginseng Research
• /
• v.44 no.4
• /
• pp.611-618
• /
• 2020

Background: It is well recognized that gut microbiota is involved in the biotransformation of ginsenosides by converting the polar ginsenosides to nonpolar bioactive ginsenosides. However, the roles of the gut microbiota on the pharmacokinetics of ginsenosides in humans have not yet been fully elucidated. Methods: Red ginseng (RG) or fermented red ginseng was orally administered to 34 healthy Korean volunteers, and the serum concentrations of the ginsenosides were determined using liquid chromatography-tandem mass spectrometry. In addition, the fecal ginsenoside Rd- and compound K (CK)eforming activities were measured. Then, the correlations between the pharmacokinetic profiles of the ginsenosides and the fecal ginsenoside-metabolizing activities were investigated. Results: For the RG group, the area under the serum concentratione-time curve values of ginsenosides Rd, F2, Rg3, and CK were 8.20 ± 11.95 ng·h/mL, 4.54 ± 3.70 ng·h/mL, 36.40 ± 19.68 ng·h/mL, and 40.30 ± 29.83 ng·h/mL, respectively. For the fermented red ginseng group, the the area under curve from zero to infinity (AUC_∞) values of ginsenosides Rd, F2, Rg3, and CK were 187.90 ± 95.87 ng·h/mL, 30.24 ± 41.87 ng·h/mL, 28.68 ± 14.27 ng·h/mL, and 137.01 ± 96.16 ng·h/mL, respectively. The fecal CK-forming activities of the healthy volunteers were generally proportional to their ginsenoside Rd-eforming activities. The area under the serum concentration-time curve value of CK exhibited an obvious positive correlation (r = 0.566, p < 0.01) with the fecal CK-forming activity. Conclusion: The gut microbiota may play an important role in the bioavailability of the nonpolar RG ginsenosides by affecting the biotransformation of the ginsenosides.

• Korean Journal of Microbiology
• /
• v.50 no.4
• /
• pp.308-312
• /
• 2014

In this study, we conducted a next generation sequencing based microbial community analysis to investigate gut microbiota of the two commercially most available swine breeds, Yorkshire and Landrace. Bacterial 16S rRNA gene was amplified from fecal DNA using universal primer sets designed for V4 regions. Our comparison analysis of the gut microbiota of the two breeds suggested that their gut microbiota changed depending on the growth stages, while the difference between the two breeds was insignificant. However, there was a limited number of genera, the abundance of which was found to be different between the breeds. Those included the genus Xylanibacter in the Yorkshire samples, which was previously reported as a fiber digesting bacteria, likely increasing energy harvesting capacity of swine. In addition, others included opportunistic pathogens mostly found in the Yorkshire samples while the Landrace samples had significantly more prevalent Clostridium_IV species that were known to play a key role in systemic immunity of hosts. While microbial community shifts was found to be associated with growth stages, the difference between the two breeds seemed to be insignificant. However, there were several bacterial genera showing differential abundance, which may affect growth of hosts.

• Journal of Life Science
• /
• v.29 no.8
• /
• pp.922-940
• /
• 2019

Obesity, represented by abnormal fat accumulation due to an imbalance between energy intake and expenditure, is a major public health issue worldwide, leading to multiple noncommunicable diseases, including atherosclerosis, hypertension, type 2 diabetes, and cancer. Diverse solutions have been proposed to combat obesity. Attention has focused on two types of adipose tissues as a promising therapeutic target in obesity: traditional brown and beige or brite. Unlike energy-storing white adipose (endocrine) tissue, traditional brown adipose tissue and beige adipose tissue have energy-dissipating thermogenic properties. Both types of tissue are present in adult humans and inducible through external stimuli, such as cold exposure, ${\beta}3$-adrenergic receptor agonists, and phytochemicals. Among these stimuli, microbiota present in the human intestinal tract participate in multiple metabolic activities. Modulation of gut microbiota may offer a potent and possibly curative strategy against various metabolic diseases. Numerous studies have focused on the effects of established antiobesity treatments on the gut microenvironment or brown-adipose-tissue activation. In this review, we focus mainly on stimuli known to alleviate obesity, weight gain, and metabolic diseases, in addition to known and possible inter-relations between gut microbiota modulation and similar interventions and adipose tissue browning. The findings may pave the way toward new strategies against obesity.

• Preventive Nutrition and Food Science
• /
• v.21 no.1
• /
• pp.57-61
• /
• 2016

Dietary proteins influence colorectal cancer (CRC) risk, depending on their quantity and quality. Here, using pyrosequencing, we compared the fecal microbiota composition in Balb/c mice fed either a normal protein/carbohydrate diet (ND, 20% casein and 68% carbohydrate) or a high-protein/low-carbohydrate diet (HPLCD, 30% casein and 57% carbohydrate). The results showed that HPLCD feeding for 2 weeks reduced the diversity and altered the composition of the microbiota compared with the ND mice, which included a decrease in the proportion of the family Lachnospiraceae and Ruminococcaceae and increases in the proportions of the genus Bacteroides and Parabacteroides, especially the species EF09600_s and EF604598_s. Similar changes were reported in patients with inflammatory bowel disease, and in mouse models of CRC and colitis, respectively. This suggests that HPLCD may lead to a deleterious luminal environment and may have adverse effects on the intestinal health of individuals consuming such a diet.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.2
• /
• pp.133-143
• /
• 2014

The development of the gut is controlled and modulated by different interacting mechanisms, such as genetic endowment, intrinsic biological regulatory functions, environment influences and last but no least, the diet influence. In this work, we compared the fecal microbiota of breast-fed (BF), formula-fed (FF), and mixed-fed (MF) infants from Hebei Province, China. By using high-throughput 16S rDNA sequencing analyses, we found some differences in gut microbiota in the three groups. Firmicutes and Proteobacteria were the dominant bacteria at the phylum level in the three groups, where FF infants showed a significant depletion in Bacteroidetes (p < 0.001) and Actinobacteria (p < 0.05). Enterobacteriaceae was the dominant bacteria at the family level in the three groups, but FF infants showed higher Enterobacteriaceae enrichment than BF and MF infants (p < 0.05); the abundance of the Bifidobacteriaceae was only 8.16% in the feces of BF infants, but higher than in MF and FF infants (p < 0.05). The number of genera detected (abundance >0.01%) in BF, MF, and FF infants was only 15, 16, and 13, respectively. This study could provide more accurate and scientific data for the future study of infant intestinal flora.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.8
• /
• pp.1247-1259
• /
• 2018

Raspberries are polyphenol-rich fruits with the potential to reduce the severity of the clinical signs associated with obesity, a phenomenon that may be related to changes in the gut microbiota. The aim of this study was to investigate the effect of raspberry supplementation on the fecal microbiota using an in vivo model of obesity. Obese diabetic db/db mice were used in this study and assigned to two experimental groups (with and without raspberry supplementation). Fecal samples were collected at the end of the supplementation period (8 weeks) and used for bacterial 16S rRNA gene profiling using a MiSeq instrument (Illumina). QIIME 1.8 was used to analyze the 16S data. Raspberry supplementation was associated with an increased abundance of Lachnospiraceae (p = 0.009), a very important group for gut health, and decreased abundances of Lactobacillus, Odoribacter, and the fiber degrader S24-7 family as well as unknown groups of Bacteroidales and Enterobacteriaceae (p < 0.05). These changes were enough to clearly differentiate bacterial communities accordingly to treatment, based on the analysis of UniFrac distance metrics. However, a predictive approach of functional profiles showed no difference between the treatment groups. Fecal metabolomic analysis provided critical information regarding the raspberry-supplemented group, whose relatively higher phytosterol concentrations may be relevant for the host health, considering the proven health benefits of these phytochemicals. Further studies are needed to investigate whether the observed differences in microbial communities (e.g., Lachnospiraceae) or metabolites relate to clinically significant differences that can prompt the use of raspberry extracts to help patients with obesity.