scholarly journals A Putative Type V Pilus Contributes toBacteroides thetaiotaomicronBiofilm Formation Capacity

2019 ◽  
Vol 201 (18) ◽  
Author(s):  
Jovana Mihajlovic ◽  
Nathalie Bechon ◽  
Christa Ivanova ◽  
Florian Chain ◽  
Alexandre Almeida ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Selection Procedure ◽  
Bacteroides Thetaiotaomicron ◽  
Human Gut ◽  
Healthy Human ◽  
Content Type ◽  
Human Gut Microbiota ◽  
Type V

ABSTRACTBacteroides thetaiotaomicronis a prominent anaerobic member of the healthy human gut microbiota. While the majority of functional studies onB. thetaiotaomicronaddressed its impact on the immune system and the utilization of diet polysaccharides,B. thetaiotaomicronbiofilm capacity and its contribution to intestinal colonization are still poorly characterized. We tested the natural adhesion of 34B. thetaiotaomicronisolates and showed that although biofilm capacity is widespread amongB. thetaiotaomicronstrains, this phenotype is masked or repressed in the widely used reference strain VPI 5482. Using transposon mutagenesis followed by a biofilm positive-selection procedure, we identified VPI 5482 mutants with increased biofilm capacity corresponding to an alteration in the C-terminal region of BT3147, encoded by theBT3148-BT3147locus, which displays homology with Mfa-like type V pili found in manyBacteroidetes. We show that BT3147 is exposed on theB. thetaiotaomicronsurface and that BT3147-dependent adhesion also requires BT3148, suggesting that BT3148 and BT3147 correspond to the anchor and stalk subunits of a new type V pilus involved inB. thetaiotaomicronadhesion. This study therefore introducesB. thetaiotaomicronas a model to study proteinaceous adhesins and biofilm-related phenotypes in this important intestinal symbiont.IMPORTANCEAlthough the gut anaerobeBacteroides thetaiotaomicronis a prominent member of the healthy human gut microbiota, little is known about its capacity to adhere to surfaces and form biofilms. Here, we identify that alteration of a surface-exposed protein corresponding to a type of pili found in manyBacteroidetesincreasesB. thetaiotaomicronbiofilm formation. This study lays the ground for establishing this bacterium as a model organism forin vitroandin vivostudies of biofilm-related phenotypes in gut anaerobes.

scholarly journals Intestinal IgA Regulates Expression of a Fructan Polysaccharide Utilization Locus in Colonizing Gut Commensal Bacteroides thetaiotaomicron

mBio ◽  
2019 ◽  
Vol 10 (6) ◽  
Author(s):  
Payal Joglekar ◽  
Hua Ding ◽  
Pablo Canales-Herrerias ◽  
Pankaj Jay Pasricha ◽  
Justin L. Sonnenburg ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Ex Vivo ◽  
Microbial Colonization ◽  
Bacteroides Thetaiotaomicron ◽  
Content Type ◽  
Microbial Utilization ◽  
Polysaccharide Utilization Locus ◽  
The Impact

ABSTRACT Gut-derived immunoglobulin A (IgA) is the most abundant antibody secreted in the gut that shapes gut microbiota composition and functionality. However, most of the microbial antigens targeted by gut IgA remain unknown, and the functional effects of IgA targeting these antigens are currently understudied. This study provides a framework for identifying and characterizing gut microbiota antigens targeted by gut IgA. We developed a small intestinal ex vivo culture assay to harvest lamina propria IgA from gnotobiotic mice, with the aim of identifying antigenic targets in a model human gut commensal, Bacteroides thetaiotaomicron VPI-5482. Colonization by B. thetaiotaomicron induced a microbe-specific IgA response that was reactive against diverse antigens, including capsular polysaccharides, lipopolysaccharides, and proteins. IgA against microbial protein antigens targeted membrane and secreted proteins with diverse functionalities, including an IgA specific against proteins of the polysaccharide utilization locus (PUL) that are necessary for utilization of fructan, which is an important dietary polysaccharide. Further analyses demonstrated that the presence of dietary fructan increased the production of fructan PUL-specific IgA, which then downregulated the expression of fructan PUL in B. thetaiotaomicron, both in vivo and in vitro. Since the expression of fructan PUL has been associated with the ability of B. thetaiotaomicron to colonize the gut in the presence of dietary fructans, our work suggests a novel role for gut IgA in regulating microbial colonization by modulating their metabolism. IMPORTANCE Given the significant impact that gut microbes have on our health, it is essential to identify key host and environmental factors that shape this diverse community. While many studies have highlighted the impact of diet on gut microbiota, little is known about how the host regulates this critical diet-microbiota interaction. In our present study, we discovered that gut IgA targeted a protein complex involved in the utilization of an important dietary polysaccharide: fructan. While the presence of dietary fructans was previously thought to allow unrestricted growth of fructan-utilizing bacteria, our work shows that gut IgA, by targeting proteins responsible for fructan utilization, provides the host with tools that can restrict the microbial utilization of such polysaccharides, thereby controlling their growth.

scholarly journals In vivo and in vitro metabolism of trans-resveratrol by human gut microbiota

2013 ◽  
Vol 97 (2) ◽  
pp. 295-309 ◽  
Author(s):  
Lisa M Bode ◽  
Diana Bunzel ◽  
Melanie Huch ◽  
Gyu-Sung Cho ◽  
Denise Ruhland ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
In Vitro Metabolism ◽  
Human Gut ◽  
Human Gut Microbiota

scholarly journals Functional heterogeneity in the fermentation capabilities of the healthy human gut microbiota

2020 ◽  
Author(s):  
Thomas Gurry ◽  
Le Thanh Tu Nguyen ◽  
Xiaoqian Yu ◽  
Eric J Alm
Keyword(s):  
Gut Microbiota ◽  
Therapeutic Strategy ◽  
Ex Vivo ◽  
Short Chain Fatty Acids ◽  
Human Gut ◽  
Healthy Human ◽  
Human Gut Microbiota ◽  
Functional Differences ◽  
Rrna Sequencing

AbstractThe human gut microbiota is known for its highly heterogeneous composition across different individuals. However, relatively little is known about functional differences in its ability to ferment complex polysaccharides. Through ex vivo measurements from healthy human donors, we show that individuals vary markedly in their microbial metabolic phenotypes (MMPs), mirroring differences in their microbiota composition, and resulting in the production of different quantities and proportions of Short Chain Fatty Acids (SCFAs) from the same inputs. We also show that aspects of these MMPs can be predicted from composition using 16S rRNA sequencing. From experiments performed using the same dietary fibers in vivo, we demonstrate that an ingested bolus of fiber is almost entirely consumed by the microbiota upon passage. We leverage our ex vivo data to construct a model of SCFA production and absorption in vivo, and argue that inter-individual differences in quantities of absorbed SCFA are directly related to differences in production. Taken together, these data suggest that personalized dietary fiber supplementation based on an individual’s MMP is an attractive therapeutic strategy for treating diseases associated with SCFA production.

Impact of tart cherries polyphenols on the human gut microbiota and phenolic metabolites in vitro and in vivo

2018 ◽  
Vol 59 ◽  
pp. 160-172 ◽  
Author(s):  
Alba C. Mayta-Apaza ◽  
Ellen Pottgen ◽  
Jana De Bodt ◽  
Nora Papp ◽  
Daya Marasini ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Human Gut ◽  
Phenolic Metabolites ◽  
Human Gut Microbiota ◽  
Tart Cherries

scholarly journals Biomarkers and Utility of the Antioxidant Potential of Probiotic Lactobacilli and Bifidobacteria as Representatives of the Human Gut Microbiota

Biomedicines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1340
Author(s):  
Olga V. Averina ◽  
Elena U. Poluektova ◽  
Mariya V. Marsova ◽  
Valery N. Danilenko
Keyword(s):  
Oxidative Stress ◽  
Gut Microbiota ◽  
Antioxidant Properties ◽  
Natural Antioxidants ◽  
Antioxidant Potential ◽  
Diagnostic Systems ◽  
Human Gut ◽  
Human Gut Microbiota

Lactobacilli and bifidobacteria are an important part of human gut microbiota. Among numerous benefits, their antioxidant properties are attracting more and more attention. Multiple in vivo and in vitro studies have demonstrated that lactobacilli and bifidobacteria, along with their cellular components, possess excellent antioxidant capacity, which provides a certain degree of protection to the human body against diseases associated with oxidative stress. Recently, lactobacilli and bifidobacteria have begun to be considered as a new source of natural antioxidants. This review summarizes the current state of research on various antioxidant properties of lactobacilli and bifidobacteria. Special emphasis is given to the mechanisms of antioxidant activity of these bacteria in the human gut microbiota, which involve bacterial cell components and metabolites. This review is also dedicated to the genes involved in the antioxidant properties of lactobacilli and bifidobacteria strains as indicators of their antioxidant potential in human gut microbiota. Identification of the antioxidant biomarkers of the gut microbiota is of great importance both for creating diagnostic systems for assessing oxidative stress and for choosing strategies aimed at restoring the normal functioning of the microbiota and, through it, restoring human health. In this review, the practical application of probiotic strains with proven antioxidant properties to prevent oxidative stress is also considered.

scholarly journals Functional heterogeneity in the fermentation capabilities of the healthy human gut microbiota

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254004
Author(s):  
Thomas Gurry ◽  
Le Thanh Tu Nguyen ◽  
Xiaoqian Yu ◽  
Eric J. Alm
Keyword(s):  
Gut Microbiota ◽  
Ex Vivo ◽  
Short Chain Fatty Acids ◽  
Human Gut ◽  
Healthy Human ◽  
Human Gut Microbiota ◽  
Functional Differences ◽  
Rrna Sequencing ◽  
Quantitative Understanding

The human gut microbiota is known for its highly heterogeneous composition across different individuals. However, relatively little is known about functional differences in its ability to ferment complex polysaccharides. Through ex vivo measurements from healthy human donors, we show that individuals vary markedly in their microbial metabolic phenotypes (MMPs), mirroring differences in their microbiota composition, and resulting in the production of different quantities and proportions of Short Chain Fatty Acids (SCFAs) from the same inputs. We also show that aspects of these MMPs can be predicted from composition using 16S rRNA sequencing. From experiments performed using the same dietary fibers in vivo, we demonstrate that an ingested bolus of fiber is almost entirely consumed by the microbiota upon passage. We leverage our ex vivo data to construct a model of SCFA production and absorption in vivo, and argue that inter-individual differences in quantities of absorbed SCFA are directly related to differences in production. Though in vivo studies are required to confirm these data in the context of the gut, in addition to in vivo read outs of SCFAs produced in response to specific fiber spike-ins, these data suggest that optimizing SCFA production in a given individual through targeted fiber supplementation requires quantitative understanding of their MMP.

scholarly journals Sharing a β-Glucan Meal: Transcriptomic Eavesdropping on a Bacteroides ovatus-Subdoligranulum variabile-Hungatella hathewayi Consortium

2020 ◽  
Vol 86 (20) ◽  
Author(s):  
Manuela Centanni ◽  
Ian M. Sims ◽  
Tracey J. Bell ◽  
Ambarish Biswas ◽  
Gerald W. Tannock
Keyword(s):  
Microbial Community ◽  
Gut Microbiota ◽  
Dietary Fiber ◽  
Bacterial Species ◽  
Human Gut ◽  
Additional Energy ◽  
Content Type ◽  
Human Gut Microbiota ◽  
Bacteroides Ovatus

ABSTRACT Whole-transcriptome analysis was used to investigate the molecular interplay between three bacterial species that are members of the human gut microbiota. Bacteroides ovatus, Subdoligranulum variabile, and Hungatella hathewayi formed associations in cocultures fed barley β-glucan, a constituent of dietary fiber. B. ovatus depolymerized β-glucan and released, but did not utilize, 3-O-β-cellobiosyl-d-glucose (DP3) and 3-O-β-cellotriosyl-d-glucose (DP4). These oligosaccharides provided growth substrates for S. variabile and H. hathewayi with a preference for DP4 in the case of the latter species. There was increased transcription of a B. ovatus mixed-linkage-β-glucan utilization locus, as well as carbohydrate transporters in S. variabile and H. hathewayi when in batch coculture. Increased transcription of the β-glucan utilization locus did not occur in continuous culture. Evidence for interactions relating to provision of cobalamin, alterations to signaling, and modulation of the “stringent response” (an adaptation to nutrient deprivation) were detected. Overall, we established a bacterial consortium based on barley β-glucan in vitro, which can be used to investigate aspects of the functional blueprint of the human gut microbiota. IMPORTANCE The microbial community, mostly composed of bacterial species, residing in the human gut degrades and ferments polysaccharides derived from plants (dietary fiber) that would not otherwise be digested. In this way, the collective metabolic actions of community members extract additional energy from the human diet. While the variety of bacteria present in the microbial community is well known, the formation of bacterial consortia, and the consequent interactions that result in the digestion of dietary polysaccharides, has not been studied extensively. The importance of our work was the establishment, under laboratory conditions, of a consortium of gut bacteria that formed around a dietary constituent commonly present in cereals. This enabled the metabolic interplay between the bacterial species to be studied. This kind of knowledge is required to construct an interactive, metabolic blueprint of the microbial community that inhabits the human gut.

scholarly journals Exploring the in vivo and in vitro metabolism of glucosinolates by human gut microbiota

2010 ◽  
Vol 24 (S1) ◽  
Author(s):  
Fei Li ◽  
Meredith AJ Hullar ◽  
Shirley AA Beresford ◽  
Johanna W Lampe
Keyword(s):  
Gut Microbiota ◽  
In Vitro Metabolism ◽  
Human Gut ◽  
Human Gut Microbiota

In vitro study of the interaction between human gut microbiota and herbal extracts using willow bark extract as an example

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
EM Pferschy-Wenzig ◽  
K Koskinen ◽  
C Moissl-Eichinger ◽  
R Bauer
Keyword(s):  
Gut Microbiota ◽  
In Vitro Study ◽  
Vitro Study ◽  
Bark Extract ◽  
Herbal Extracts ◽  
Human Gut ◽  
Human Gut Microbiota ◽  
Willow Bark
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