scholarly journals A Common Pathway for Activation of Host-Targeting and Bacteria-Targeting Toxins in Human Intestinal Bacteria

mBio ◽  
2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Yiqiao Bao ◽  
Andrew A. Verdegaal ◽  
Brent W. Anderson ◽  
Natasha A. Barry ◽  
Jing He ◽  
...  
Keyword(s):  
Microbial Community ◽  
Gut Microbiome ◽  
Intestinal Bacteria ◽  
Human Intestine ◽  
Common Pathway ◽  
Antibacterial Protein ◽  
Human Intestinal Bacteria ◽  
Complex Microbial Community

The human intestine harbors a highly complex microbial community; interpersonal variation in this community can impact pathogen susceptibility, metabolism, and other aspects of health. Here, we identified and characterized a commensal-targeting antibacterial protein encoded in the gut microbiome.

scholarly journals Metagenomic Profiles of the Intestinal Virome of Long-Livers

2022 ◽  
Author(s):  
Elizaveta V. Starikova ◽  
Ksenia M. Klimina ◽  
Anastasia O. Eudokimova ◽  
Ksenia A. Yeruslanova ◽  
Denis A. Gudkov ◽  
...  
Keyword(s):  
Microbial Community ◽  
Gut Microbiome ◽  
Age Groups ◽  
The Elderly ◽  
Viral Metagenomics ◽  
Viral Diversity ◽  
Human Intestine ◽  
Health It ◽  
Beneficial Bacteria ◽  
Keywords Aging

The microbial community of the human intestine is important for maintaining human health. It has been reported that the gut microbiome changes with age, and it can be enrichedwith certain beneficial bacteria while also losing certain commensal bacteria.Little is known about the gut virome of long-livers. Our research aimed to extract, sequence and analyze the viral fraction of long-livers’ gut microbiota in comparison with those of young adults and the elderly. We were thereby able to characterize the gut virome profiles and viral diversity of three age groups. Keywords: aging, gut microbiome, viral metagenomics, bacteriophages

Bioactivation of Selenocysteine Derivatiives by β-Lyases Present in Common Gastrointestinal Bacterial Species

2008 ◽  
Vol 78 (45) ◽  
pp. 169-174 ◽  
Author(s):  
Andreas Schwiertz ◽  
Stefanie Deubel ◽  
Marc Birringer
Keyword(s):  
High Performance ◽  
Bacterial Species ◽  
Intestinal Bacteria ◽  
Human Intestine ◽  
Test Compound ◽  
Bacterial Strains ◽  
Selenium Compounds ◽  
Human Intestinal Bacteria ◽  
Lyase Activity ◽  
Specific Activities

Studies in cell cultures and animal models have demonstrated cancer chemopreventive effects of certain selenium compounds. Here we describe the screening of cysteine S-conjugate β-lyase activity in bacterial species that are implicated in the bio-activation of sulfur- and selenocysteine derivatives. We screened a range of bacterial species commonly found in the human intestine for β-lyase activity on Se-p-methoxybenzylselenocysteine and the natural occurring S-methylcysteine and Se-methylselenocysteine conjugates. A high-performance liquid chromatography (HPLC)-assisted assay was established to determine specific acctivities of each strain. Of the 29 tested bacterial species, 22 showed specific activities towards the test compound reaching up to 10.1 U/mg protein, thereby accounting for 75% of total fecal activity (13.3. U/mg protein). Lysates of four bacterial strains (Bacteroides distasonis, bacteroides vulgatus, Enterococcus faecalis, and Enterococcus faecium), which exhibited high specific activities towards the test compound and which are known to be present at high numbers in the human intestine, were characterized further. Our results indicate that β-lyase activity is widely distributed in human intestinal bacteria and might play a key role in the bioactivation of selenocysteine derivatives.

scholarly journals Lack of Evidence that Ursodeoxycholic Acid’s Effects on the Gut Microbiome Influence Colorectal Adenoma Risk

2017 ◽  
Author(s):  
Talima Pearson ◽  
J. Gregory Caporaso ◽  
Monica Yellowhair ◽  
Nicholas A. Bokulich ◽  
Denise J. Roe ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Bile Acid ◽  
Microbial Community ◽  
Colorectal Adenoma ◽  
Gut Microbiome ◽  
Intestinal Bacteria ◽  
List Type ◽  
Distance Metrics ◽  
Anti Cancer ◽  
Adenoma Risk

AbstractObjectiveWe previously reported that Ursodeoxycholic acid (UDCA), a therapeutic bile acid, reduces risk for advanced colorectal adenoma in men but not women. Interactions between the gut microbiome and fecal bile acid composition as a factor in colon cancer neoplasia have been postulated but evidence is limited to small cohorts and animal studies.DesignUsing banked stool samples collected as part of a phase III randomized clinical trial of UDCA for the prevention of colorectal neoplasia, we compared change in the microbiome composition after 3 years intervention in a subset of participants randomized to 8–10 mg/kg of body weight UDCA (n=198) to placebo (n=203). UDCA effects on the microbiome, sex and adenoma outcome were investigated.ResultsStudy participants randomized to UDCA experienced compositional changes in their microbiome that were statistically more similar to other individuals in the UDCA arm than to those in the placebo arm. This change reflected an UDCA-associated shift in microbial community distance metrics (P <0.001), independent of sex, with no evidence of UDCA effect on microbial richness (P > 0.05). These UDCA-associated shifts in microbial community distance metrics from baseline to end-of-study were not associated with risk of any or advanced adenoma (all P> 0.05) in men or women.ConclusionDespite a large sampling of randomized clinical trial participants, daily UDCA use only modestly influenced the relative abundance of microbial species in stool with no evidence for effects of UDCA on stool microbial community composition as a modifier of colorectal adenoma risk.SUMMARYWhat is already known about this subject?Ursodeoxycholic acid (UDCA) is a therapeutic bile acid used in the treatment of primary biliary cirrhosis (PBC) and investigated for anti-cancer activity in the colonIn humans, UDCA is produced in the colon from the conjugation of primary bile acids by intestinal bacteriaIntestinal bacteria play a critical role in human intestinal health and disease including a hypothesized role in the development of colorectal cancer.UDCA was found to reduce the risk of more advanced colorectal adenoma with effects present in men but not women.Therapeutic UDCA was recently shown to reduce the extent of bacterial dysbiosis in patients with PBCWhat are the new findings?Among a population of patients with colorectal adenoma, low dose oral UDCA taken daily produced modest changes in fecal bacterial compositionUDCA associated changes in the gut microbiome were similar in men and women.UDCA associated changes in the gut micobiome were not associated with risk of any or advanced colorectal adenoma in the patient population.How might it impact on clinical practice in the foreseeable future?These findings confirm effects of oral UDCA on the microbiome that may be beneficial for patients with PBC.These findings suggest that the anti-cancer effects of UDCA for colorectal adenoma prevention are not due to major effects of UDCA on the gut microbiome.

scholarly journals Exploring the taxonomical and functional profile of As Burgas hot spring focusing on thermostable β-galactosidases

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
María-Eugenia DeCastro ◽  
Michael P. Doane ◽  
Elizabeth Ann Dinsdale ◽  
Esther Rodríguez-Belmonte ◽  
María-Isabel González-Siso
Keyword(s):  
Microbial Community ◽  
Hot Spring ◽  
Functional Characterization ◽  
Tca Cycle ◽  
Maximal Activity ◽  
Sulfur Cycle ◽  
E Coli ◽  
Complex Microbial Community ◽  
Relationship Of ◽  
The Relationship

AbstractIn the present study we investigate the microbial community inhabiting As Burgas geothermal spring, located in Ourense (Galicia, Spain). The approximately 23 Gbp of Illumina sequences generated for each replicate revealed a complex microbial community dominated by Bacteria in which Proteobacteria and Aquificae were the two prevalent phyla. An association between the two most prevalent genera, Thermus and Hydrogenobacter, was suggested by the relationship of their metabolism. The high relative abundance of sequences involved in the Calvin–Benson cycle and the reductive TCA cycle unveils the dominance of an autotrophic population. Important pathways from the nitrogen and sulfur cycle are potentially taking place in As Burgas hot spring. In the assembled reads, two complete ORFs matching GH2 beta-galactosidases were found. To assess their functional characterization, the two ORFs were cloned and overexpressed in E. coli. The pTsbg enzyme had activity towards o-Nitrophenyl-β-d-galactopyranoside (ONPG) and p-Nitrophenyl-β-d-fucopyranoside, with high thermal stability and showing maximal activity at 85 °C and pH 6, nevertheless the enzyme failed to hydrolyze lactose. The other enzyme, Tsbg, was unable to hydrolyze even ONPG or lactose. This finding highlights the challenge of finding novel active enzymes based only on their sequence.

scholarly journals The phyllosphere microbiome of host trees contributes more than leaf phytochemicals to variation in the Agrilus planipennis Fairmaire gut microbiome structure

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Judith Mogouong ◽  
Philippe Constant ◽  
Pierre Legendre ◽  
Claude Guertin
Keyword(s):  
Microbial Community ◽  
Gut Microbiome ◽  
Strong Predictor ◽  
Emerald Ash Borer ◽  
Agrilus Planipennis ◽  
Food Sources ◽  
Microbiome Composition ◽  
Living Organisms ◽  
Insect Gut ◽  
Gut Microbial Community

AbstractThe microbiome composition of living organisms is closely linked to essential functions determining the fitness of the host for thriving and adapting to a particular ecosystem. Although multiple factors, including the developmental stage, the diet, and host-microbe coevolution have been reported to drive compositional changes in the microbiome structures, very few attempts have been made to disentangle their various contributions in a global approach. Here, we focus on the emerald ash borer (EAB), an herbivorous pest and a real threat to North American ash tree species, to explore the responses of the adult EAB gut microbiome to ash leaf properties, and to identify potential predictors of EAB microbial variations. The relative contributions of specific host plant properties, namely bacterial and fungal communities on leaves, phytochemical composition, and the geographical coordinates of the sampling sites, to the EAB gut microbial community was examined by canonical analyses. The composition of the phyllosphere microbiome appeared to be a strong predictor of the microbial community structure in EAB guts, explaining 53 and 48% of the variation in fungi and bacteria, respectively. This study suggests a potential covariation of the microorganisms associated with food sources and the insect gut microbiome.

scholarly journals Degradation of bile salts by human intestinal bacteria.

Gut ◽  
1968 ◽  
Vol 9 (1) ◽  
pp. 22-27 ◽  
Author(s):  
M J Hill ◽  
B S Drasar
Keyword(s):  
Bile Salts ◽  
Intestinal Bacteria ◽  
Human Intestinal Bacteria
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