scholarly journals Polyclonal Aptamers for Specific Fluorescence Labeling and Quantification of the Health Relevant Human Gut Bacterium Parabacteroides distasonis

2021 ◽  
Vol 9 (11) ◽  
pp. 2284
Author(s):  
Hu Xing ◽  
Ann-Kathrin Kissmann ◽  
Heinz Fabian Raber ◽  
Markus Krämer ◽  
Valerie Amann ◽  
...  
Keyword(s):  
Intestinal Bacteria ◽  
Probiotic Bacterium ◽  
Gut Bacteria ◽  
Fluorescence Labeling ◽  
Diagnostic Tools ◽  
Human Gut ◽  
Alcoholic Fatty Liver ◽  
Whole Cells ◽  
Cell Counts ◽  
Quantitative Monitoring

Single-stranded DNA aptamers as affinity molecules for the rapid, reliable detection of intestinal bacteria are of particular interest to equip health systems with novel robust and cheap diagnostic tools for monitoring the success of supplementation strategies with selected probiotic gut bacteria in the fight against major widespread threats, such as obesity and neurodegenerative diseases. The human gut bacterium Parabacteroides distasonis (P. distasonis) is positively associated with diseases such as obesity, non-alcoholic fatty liver disease and multiple sclerosis with reduced cell counts in these diseases and is thus a promising potential probiotic bacterium for future microbial supplementation. In this paper we report on the evolution of a specific polyclonal aptamer library by the fluorescence based FluCell-SELEX directed against whole cells of P. distasonis that specifically and efficiently binds and labels P. distasonis. The aptamer library showed high binding affinity and was suited to quantitatively discriminate P. distasonis from other prominent gut bacteria also in mixtures. We believe that this library against a promising probiotic bacterium as a prototype may open new routes towards the development of novel biosensors for the easy and efficient quantitative monitoring of microbial abundance in human microbiomes in general.

scholarly journals Metabolism of Linoleic Acid by Human Gut Bacteria: Different Routes for Biosynthesis of Conjugated Linoleic Acid

2007 ◽  
Vol 189 (6) ◽  
pp. 2566-2570 ◽  
Author(s):  
Estelle Devillard ◽  
Freda M. McIntosh ◽  
Sylvia H. Duncan ◽  
R. John Wallace
Keyword(s):  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Vaccenic Acid ◽  
Intestinal Bacteria ◽  
Gut Bacteria ◽  
Human Tissues ◽  
Human Gut ◽  
Gram Positive ◽  
Health Promoting

ABSTRACT A survey of 30 representative strains of human gram-positive intestinal bacteria indicated that Roseburia species were among the most active in metabolizing linoleic acid (cis-9,cis-12-18:2). Different Roseburia spp. formed either vaccenic acid (trans-11-18:1) or a 10-hydroxy-18:1; these compounds are precursors of the health-promoting conjugated linoleic acid cis-9,trans-11-18:2 in human tissues and the intestine, respectively.

scholarly journals Contribution of gut bacteria to the metabolism of cyanidin 3-glucoside in human microbiota-associated rats

2012 ◽  
Vol 109 (8) ◽  
pp. 1433-1441 ◽  
Author(s):  
Laura Hanske ◽  
Wolfram Engst ◽  
Gunnar Loh ◽  
Silke Sczesny ◽  
Michael Blaut ◽  
...  
Keyword(s):  
Intestinal Bacteria ◽  
Hydroxycinnamic Acid ◽  
Gut Bacteria ◽  
Dihydroxybenzoic Acid ◽  
Human Gut ◽  
Germ Free ◽  
Human Microbiota ◽  
Human Intestinal Bacteria ◽  
The Impact

Cyanidin 3-glucoside (C3G) is one of the major dietary anthocyanins implicated in the prevention of chronic diseases. To evaluate the impact of human intestinal bacteria on the fate of C3G in the host, we studied the metabolism of C3G in human microbiota-associated (HMA) rats in comparison with germ-free (GF) rats. Urine and faeces of the rats were analysed for C3G and its metabolites within 48 h after the application of 92 μmol C3G/kg body weight. In addition, we tested the microbial C3G conversion in vitro by incubating C3G with human faecal slurries and selected human gut bacteria. The HMA rats excreted with faeces a three times higher percentage of unconjugated C3G products and a two times higher percentage of conjugated C3G products than the GF rats. These differences were mainly due to the increased excretion of 3,4-dihydroxybenzoic acid, 2,4,6-trihydroxybenzaldehyde and 2,4,6-trihydroxybenzoic acid. Only the urine of HMA rats contained peonidin and 3-hydroxycinnamic acid and the percentage of conjugated C3G products in the urine was decreased compared with the GF rats. Overall, the presence of intestinal microbiota resulted in a 3·7 % recovery of the C3G dose in HMA rats compared with 1·7 % in GF rats. Human intestinal bacteria rapidly degraded C3G in vitro. Most of the C3G products were also found in the absence of bacteria, but at considerably lower levels. The higher concentrations of phenolic acids observed in the presence of intestinal bacteria may contribute to the proposed beneficial health effects of C3G.

scholarly journals Flavonoid-Modifying Capabilities of the Human Gut Microbiome—An In Silico Study

Nutrients ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 2688
Author(s):  
Tobias Goris ◽  
Rafael R. C. Cuadrat ◽  
Annett Braune
Keyword(s):  
Gut Microbiome ◽  
Large Scale ◽  
Health Impact ◽  
Gut Bacteria ◽  
Human Gut ◽  
Positive Health ◽  
Human Gut Microbiome ◽  
Nutritional Recommendations ◽  
Genes Encoding ◽  
A Minor

Flavonoids are a major group of dietary plant polyphenols and have a positive health impact, but their modification and degradation in the human gut is still widely unknown. Due to the rise of metagenome data of the human gut microbiome and the assembly of hundreds of thousands of bacterial metagenome-assembled genomes (MAGs), large-scale screening for potential flavonoid-modifying enzymes of human gut bacteria is now feasible. With sequences of characterized flavonoid-transforming enzymes as queries, the Unified Human Gastrointestinal Protein catalog was analyzed and genes encoding putative flavonoid-modifying enzymes were quantified. The results revealed that flavonoid-modifying enzymes are often encoded in gut bacteria hitherto not considered to modify flavonoids. The enzymes for the physiologically important daidzein-to-equol conversion, well studied in Slackiaisoflavoniconvertens, were encoded only to a minor extent in Slackia MAGs, but were more abundant in Adlercreutzia equolifaciens and an uncharacterized Eggerthellaceae species. In addition, enzymes with a sequence identity of about 35% were encoded in highly abundant MAGs of uncultivated Collinsella species, which suggests a hitherto uncharacterized daidzein-to-equol potential in these bacteria. Of all potential flavonoid modification steps, O-deglycosylation (including derhamnosylation) was by far the most abundant in this analysis. In contrast, enzymes putatively involved in C-deglycosylation were detected less often in human gut bacteria and mainly found in Agathobacter faecis (formerly Roseburia faecis). Homologs to phloretin hydrolase, flavanonol/flavanone-cleaving reductase and flavone reductase were of intermediate abundance (several hundred MAGs) and mainly prevalent in Flavonifractor plautii. This first comprehensive insight into the black box of flavonoid modification in the human gut highlights many hitherto overlooked and uncultured bacterial genera and species as potential key organisms in flavonoid modification. This could lead to a significant contribution to future biochemical-microbiological investigations on gut bacterial flavonoid transformation. In addition, our results are important for individual nutritional recommendations and for biotechnological applications that rely on novel enzymes catalyzing potentially useful flavonoid modification reactions.

Coculture of primary human colon monolayer with human gut bacteria

2021 ◽  
Author(s):  
Jianbo Zhang ◽  
Victor Hernandez-Gordillo ◽  
Martin Trapecar ◽  
Charles Wright ◽  
Mao Taketani ◽  
...  
Keyword(s):  
Human Colon ◽  
Gut Bacteria ◽  
Human Gut

Direct cloning of genes encoding novel xylanases from the human gut

2005 ◽  
Vol 51 (3) ◽  
pp. 251-259 ◽  
Author(s):  
Hidenori Hayashi ◽  
Takashi Abe ◽  
Mitsuo Sakamoto ◽  
Hiroki Ohara ◽  
Toshimichi Ikemura ◽  
...  
Keyword(s):  
Intestinal Bacteria ◽  
Fecal Microbiota ◽  
Coli Strain ◽  
Amino Acid Sequences ◽  
Self Organizing Map ◽  
Human Gut ◽  
Gene Encoding ◽  
Genes Encoding ◽  
Ph Range ◽  
Self Organizing

The aim of this study was to identify a novel 1,4-β-xylanase gene from the mixed genome DNA of human fecal bacteria without bacterial cultivation. Total DNA was isolated from a population of bacteria extracted from fecal microbiota. Using PCR, the gene fragments encoding 5 different family 10 xylanases (xyn10A, xyn10B, xyn10C, xyn10D, and xyn10E) were found. Amino acid sequences deduced from these genes were highly homologous with those of xylanases from anaerobic intestinal bacteria such as Bacteroides spp. and Prevotella spp. Self-organizing map (SOM) analysis revealed that xynA10 was classified into Bacteroidetes. To confirm that one of these genes encodes an active enzyme, a full-length xyn10A gene was obtained using nested primers specific to the internal fragments and random primers. The xyn10A gene encoding the xylanase Xyn10A consists of 1146 bp and encodes a protein of 382 amino acids and a molecular weight of 43 552. Xyn10A was a single module novel xylanase. Xyn10A was purified from a recombinant Escherichia coli strain and characterized. This enzyme was optimally active at 40 °C and stable up to 50 °C at pH 6.5 and over the pH range 4.0–11.0 at 25 °C. In addition, 2 ORFs (ORF1 and ORF2) were identified upstream of xyn10A. These results suggested that many unidentified xylanolytic bacteria exist in the human gut and may contribute to the breakdown of xylan which contains dietary fiber.Key words: xylanase, human gut, fecal microbiota, phylogenetic analysis, self-organizing map.

scholarly journals Selective fermentation of gentiobiose-derived oligosaccharides by human gut bacteria and influence of molecular weight

2006 ◽  
Vol 56 (3) ◽  
pp. 383-388 ◽  
Author(s):  
María Luz Sanz ◽  
Gregory L. Côté ◽  
Glenn R. Gibson ◽  
Robert A. Rastall
Keyword(s):  
Molecular Weight ◽  
Gut Bacteria ◽  
Human Gut
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