Browsing by Author "Hyun Cha, Kwang"

Now showing 1 - 3 of 3

Emodin modulates gut microbial community and triggers intestinal immunity
(John Wiley & Sons Ltd, 2022) Mabwi, Humphrey A.; Lee, Hee Ju; Hitayezu, Emmanuel; Mauliasari, Intan Rizki; Pan, Cheol-Ho; Mwaikono, Kilaza Samson; Komba, Erick V. G.; Lee, Choong-Gu; Hyun Cha, Kwang
BACKGROUND: The gut microbiota (GM) plays an important role in human health and is being investigated as a possible target for new therapies. Although there are many studies showing that emodin can improve host health, emodin–GM studies are scarce. Here, the effects of emodin on the GM were investigated in vitro and in vivo. RESULTS: In vitro single bacteria cultivation showed that emodin stimulated the growth of beneficial bacteria Akkermansia, Clostridium, Roseburia, and Ruminococcus but inhibited major gut enterotypes (Bacteroides and Prevotella). Microbial community analysis from a synthetic gut microbiome model through co-culture indicated the consistent GM change by emodin. Interestingly, emodin stimulated Clostridium and Ruminococcus (which are related to Roseburia and Faecalibacterium) in a mice experiment and induced anti-inflammatory immune cells, which may correlate with its impact on specific gut bacteria. CONCLUSION: Emodin (i) showed similar GM changes in monoculture, co-culture, and in an in vivo mice experiment and (ii) simulated regulatory T-cell immune responses in vivo. This suggest that emodin may be used to modulate the GM and improve health.
Susceptibility of campylobacter strains to selected natural products and frontline antibiotics
(MDPI, 2020) Gahamanyi, Noel; Song, Dae-Geun; Hyun Cha, Kwang; Yoon, Kye-Yoon; Leonard E.; Mboera, G.; Matee, Mecky I.; Mutangana, Dieudonné; Amachawadi, Raghavendra G.; Komba, Erick V. G.; Pan, Cheol-Ho
Campylobacter species have developed resistance to existing antibiotics. The development of alternative therapies is, therefore, a necessity. This study evaluates the susceptibility of Campylobacter strains to selected natural products (NPs) and frontline antibiotics. Two C. jejuni strains (ATCC® 33560TM and MT947450) and two C. coli strains (ATCC® 33559TM and MT947451) were used. The antimicrobial potential of the NPs, including plant extracts, essential oils, and pure phytochemicals, was evaluated by broth microdilution. The growth was measured by spectrophotometry and iodonitrotetrazolium chloride. Antibiotic resistance genes (tet(O) and gyrA) were characterized at the molecular level. The minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) ranged from 25 to 1600 μg/mL. Cinnamon oil, (E)-Cinnamaldehyde, clove oil, eugenol, and baicalein had the lowest MIC and MBC values (25–100 μg/mL). MT947450 and MT947451 were sensitive to erythromycin and gentamicin but resistant to quinolones and tetracycline. Mutations in gyrA and tet(O) genes from resistant strains were confirmed by sequencing. The findings show that NPs are effective against drug-sensitive and drug-resistant Campylobacter strains. The resistance to antibiotics was confirmed at phenotypic and genotypic levels. This merits further studies to decipher the action mechanisms and synergistic activities of NPs
Synthetic gut microbiome: Advances and challenges
(Elsevier, 2020) Mabwi, Humphrey A.; Kim, Eunjung; Song, Dae-Geun; Yoon, Hyo Shin; Pan, Cheol-Ho; Komba, Erick V.G.; Ko, GwangPyo; Hyun Cha, Kwang
An exponential rise in studies regarding the association among human gut microbial communities, human health, and diseases is currently attracting the attention of researchers to focus on human gut microbiome research. However, even with the ever-growing number of studies on the human gut micro- biome, translation into improved health is progressing slowly. This hampering is due to the complexities of the human gut microbiome, which is composed of >1,000 species of microorganisms, such as bacteria, archaea, viruses, and fungi. To overcome this complexity, it is necessary to reduce the gut microbiome, which can help simplify experimental variables to an extent, such that they can be deliberately manip- ulated and controlled. Reconstruction of synthetic or established gut microbial communities would make it easier to understand the structure, stability, and functional activities of the complex microbial commu- nity of the human gut. Here, we provide an overview of the developments and challenges of the synthetic human gut microbiome, and propose the incorporation of multi-omics and mathematical methods in a better synthetic gut ecosystem design, for easy translation of microbiome information to therapies.