scholarly journals “Bacillus massilionigeriensis”, a new bacterial species isolated from the human gut microbiota

2016 ◽  
Vol 1 ◽  
pp. 1-2
Author(s):  
Maryam Tidjani Alou ◽  
Souleymane Brah ◽  
Jeremy Delerce ◽  
Frédéric Cadoret ◽  
Pierre-Edouard Fournier ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Bacterial Species ◽  
Human Gut ◽  
Human Gut Microbiota

Substrate use prioritization by a coculture of five species of gut bacteria fed mixtures of arabinoxylan, xyloglucan, β-glucan, and pectin

2020 ◽  
Author(s):  
Y Liu ◽  
AL Heath ◽  
B Galland ◽  
N Rehrer ◽  
L Drummond ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Dietary Fiber ◽  
Plant Cell Wall ◽  
Bacterial Species ◽  
Short Chain ◽  
Emergent Properties ◽  
Human Gut ◽  
Fermentation Products ◽  
Plant Polysaccharides ◽  
Human Gut Microbiota

© 2020 American Society for Microbiology. Dietary fiber provides growth substrates for bacterial species that belong to the colonic microbiota of humans. The microbiota degrades and ferments substrates, producing characteristic short-chain fatty acid profiles. Dietary fiber contains plant cell wall-associated polysaccharides (hemicelluloses and pectins) that are chemically diverse in composition and structure. Thus, depending on plant sources, dietary fiber daily presents the microbiota with mixtures of plant polysaccharides of various types and complexity. We studied the extent and preferential order in which mixtures of plant polysaccharides (arabinoxylan, xyloglucan, β-glucan, and pectin) were utilized by a coculture of five bacterial species (Bacteroides ovatus, Bifidobacterium longum subspecies longum, Megasphaera elsdenii, Ruminococcus gnavus, and Veillonella parvula). These species are members of the human gut microbiota and have the biochemical capacity, collectively, to degrade and ferment the polysaccharides and produce short-chain fatty acids (SCFAs). B. ovatus utilized glycans in the order β-glucan, pectin, xyloglucan, and arabinoxylan, whereas B. longum subsp. longum utilization was in the order arabinoxylan, arabinan, pectin, and β-glucan. Propionate, as a proportion of total SCFAs, was augmented when polysaccharide mixtures contained galactan, resulting in greater succinate production by B. ovatus and conversion of succinate to propionate by V. parvula. Overall, we derived a synthetic ecological community that carries out SCFA production by the common pathways used by bacterial species for this purpose. Systems like this might be used to predict changes to the emergent properties of the gut ecosystem when diet is altered, with the aim of beneficially affecting human physiology. This study addresses the question as to how bacterial species, characteristic of the human gut microbiota, collectively utilize mixtures of plant polysaccharides such as are found in dietary fiber. Five bacterial species with the capacity to degrade polymers and/or produce acidic fermentation products detectable in human feces were used in the experiments. The bacteria showed preferential use of certain polysaccharides over others for growth, and this influenced their fermentation output qualitatively. These kinds of studies are essential in developing concepts of how the gut microbial community shares habitat resources, directly and indirectly, when presented with mixtures of polysaccharides that are found in human diets. The concepts are required in planning dietary interventions that might correct imbalances in the functioning of the human microbiota so as to support measures to reduce metabolic conditions such as obesity.

scholarly journals Lactobacillus caccae sp. nov., a new bacterial species isolated from the human gut microbiota

2020 ◽  
Author(s):  
Niokhor DIONE ◽  
Cheikh LO ◽  
Patricia Fern ndez Mellado G MEZ ◽  
Vicky MERHEJ ◽  
Issa Isaac NGOM ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Bacterial Species ◽  
Human Gut ◽  
Human Gut Microbiota

scholarly journals Positive Synergistic Effects of Quercetin and Rice Bran on Human Gut Microbiota Reduces Enterobacteriaceae Family Abundance and Elevates Propionate in a Bioreactor Model

2021 ◽  
Vol 12 ◽  
Author(s):  
Sudeep Ghimire ◽  
Supapit Wongkuna ◽  
Ranjini Sankaranarayanan ◽  
Elizabeth P. Ryan ◽  
G. Jayarama Bhat ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Rice Bran ◽  
Synergistic Effects ◽  
Bacterial Species ◽  
Positive Influence ◽  
Human Gut ◽  
Fatty Acid Production ◽  
Microbiome Composition ◽  
Human Gut Microbiota

Dietary fiber and flavonoids have substantial influence on the human gut microbiota composition that significantly impact health. Recent studies with dietary supplements such as quercetin and rice bran have shown beneficial impacts on the host alongside a positive influence of the gut microbiota. The specific bacterial species impacted by quercetin or rice bran in the diet is not well understood. In this study, we used a minibioreactor array system as a model to determine the effect of quercetin and rice bran individually, as well as in combination, on gut microbiota without the confounding host factors. We found that rice bran exerts higher shift in gut microbiome composition when compared to quercetin. At the species level, Acidaminococcus intestini was the only significantly enriched taxa when quercetin was supplemented, while 15 species were enriched in rice bran supplementation and 13 were enriched when quercetin and rice bran were supplemented in combination. When comparing the short chain fatty acid production, quercetin supplementation increased isobutyrate production while propionate dominated the quercetin and rice bran combined group. Higher levels of propionate were highly correlated to the lower abundance of the potentially pathogenic Enterobacteriaceae family. These findings suggest that the combination of quercetin and rice bran serve to enrich beneficial bacteria and reduce potential opportunistic pathogens. In vivo studies are necessary to determine how this synergy of quercetin and rice bran on microbiota impact host health.

scholarly journals Substrate Use Prioritization by a Coculture of Five Species of Gut Bacteria Fed Mixtures of Arabinoxylan, Xyloglucan, β-Glucan, and Pectin

2019 ◽  
Vol 86 (2) ◽  
Author(s):  
Yafei Liu ◽  
Anne-Louise Heath ◽  
Barbara Galland ◽  
Nancy Rehrer ◽  
Lynley Drummond ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Dietary Fiber ◽  
Bacterial Species ◽  
Short Chain ◽  
Emergent Properties ◽  
Human Gut ◽  
Fermentation Products ◽  
Plant Polysaccharides ◽  
Content Type ◽  
Human Gut Microbiota

ABSTRACT Dietary fiber provides growth substrates for bacterial species that belong to the colonic microbiota of humans. The microbiota degrades and ferments substrates, producing characteristic short-chain fatty acid profiles. Dietary fiber contains plant cell wall-associated polysaccharides (hemicelluloses and pectins) that are chemically diverse in composition and structure. Thus, depending on plant sources, dietary fiber daily presents the microbiota with mixtures of plant polysaccharides of various types and complexity. We studied the extent and preferential order in which mixtures of plant polysaccharides (arabinoxylan, xyloglucan, β-glucan, and pectin) were utilized by a coculture of five bacterial species (Bacteroides ovatus, Bifidobacterium longum subspecies longum, Megasphaera elsdenii, Ruminococcus gnavus, and Veillonella parvula). These species are members of the human gut microbiota and have the biochemical capacity, collectively, to degrade and ferment the polysaccharides and produce short-chain fatty acids (SCFAs). B. ovatus utilized glycans in the order β-glucan, pectin, xyloglucan, and arabinoxylan, whereas B. longum subsp. longum utilization was in the order arabinoxylan, arabinan, pectin, and β-glucan. Propionate, as a proportion of total SCFAs, was augmented when polysaccharide mixtures contained galactan, resulting in greater succinate production by B. ovatus and conversion of succinate to propionate by V. parvula. Overall, we derived a synthetic ecological community that carries out SCFA production by the common pathways used by bacterial species for this purpose. Systems like this might be used to predict changes to the emergent properties of the gut ecosystem when diet is altered, with the aim of beneficially affecting human physiology. IMPORTANCE This study addresses the question as to how bacterial species, characteristic of the human gut microbiota, collectively utilize mixtures of plant polysaccharides such as are found in dietary fiber. Five bacterial species with the capacity to degrade polymers and/or produce acidic fermentation products detectable in human feces were used in the experiments. The bacteria showed preferential use of certain polysaccharides over others for growth, and this influenced their fermentation output qualitatively. These kinds of studies are essential in developing concepts of how the gut microbial community shares habitat resources, directly and indirectly, when presented with mixtures of polysaccharides that are found in human diets. The concepts are required in planning dietary interventions that might correct imbalances in the functioning of the human microbiota so as to support measures to reduce metabolic conditions such as obesity.

scholarly journals Surface Exposure and Packing of Lipoproteins into Outer Membrane Vesicles Are Coupled Processes inBacteroides

mSphere ◽  
2018 ◽  
Vol 3 (6) ◽  
Author(s):  
Ezequiel Valguarnera ◽  
Nichollas E. Scott ◽  
Philippe Azimzadeh ◽  
Mario F. Feldman
Keyword(s):  
Gut Microbiota ◽  
Public Goods ◽  
Outer Membrane ◽  
Bacterial Species ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Alpha Amylase ◽  
Coupled Processes ◽  
Human Gut ◽  
Human Gut Microbiota

ABSTRACTOuter membrane vesicles (OMVs) are spherical structures derived from the outer membranes (OMs) of Gram-negative bacteria.Bacteroidesspp. are prominent components of the human gut microbiota, and OMVs produced by these species are proposed to play key roles in gut homeostasis. OMV biogenesis inBacteroidesis a poorly understood process. Here, we revisited the protein composition ofBacteroides thetaiotaomicronOMVs by mass spectrometry. We confirmed that OMVs produced by this organism contain large quantities of glycosidases and proteases, with most of them being lipoproteins. We found that most of these OMV-enriched lipoproteins are encoded by polysaccharide utilization loci (PULs), such as thesusoperon. We examined the subcellular locations of the components of the Sus system and found a split localization; the alpha-amylase SusG is highly enriched in OMVs, while the oligosaccharide importer SusC remains mostly in the OM. We found that all OMV-enriched lipoproteins possess a lipoprotein export sequence (LES), and we show that this signal mediates translocation of SusG from the periplasmic face of the OM toward the extracellular milieu. Mutations in the LES motif caused defects in surface exposure and recruitment of SusG into OMVs. These experiments link, for the first time, surface exposure to recruitment of proteins into OMVs. We also show that surface-exposed SusG in OMVs is active and rescues the growth of bacterial cells incapable of growing on starch as the only carbon source. Our results support the role of OMVs as “public goods” that can be utilized by other organisms with different metabolic capabilities.IMPORTANCESpecies from theBacteroidesgenus are predominant members of the human gut microbiota. OMVs inBacteroideshave been shown to be important for the homeostasis of complex host-commensal relationships, mainly involving immune tolerance and protection from disease. OMVs carry many enzymatic activities involved in the cleavage of complex polysaccharides and have been proposed as public goods that can provide growth to other bacterial species by release of polysaccharide breakdown products into the gut lumen. This work shows that the presence of a negatively charged rich amino acid motif (LES) is required for efficient packing of the surface-exposed alpha-amylase SusG into OMVs. Our findings strongly suggest that surface exposure is coupled to packing ofBacteroideslipoproteins into OMVs. This is the first step in the generation of tailor-made probiotic interventions that can exploit LES-related sequences to generateBacteroidesstrains displaying proteins of interest in OMVs.

scholarly journals Gilbert’s Syndrome and the Gut Microbiota – Insights From the Case-Control BILIHEALTH Study

2021 ◽  
Vol 11 ◽  
Author(s):  
Patrick A. Zöhrer ◽  
Claudia A. Hana ◽  
Nazlisadat Seyed Khoei ◽  
Christine Mölzer ◽  
Marlies Hörmann-Wallner ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Bacterial Species ◽  
Elevated Serum ◽  
Study Groups ◽  
Rrna Gene ◽  
Human Gut ◽  
Gilbert’S Syndrome ◽  
Alpha And Beta Diversity ◽  
Human Gut Microbiota ◽  
Gilbert's Syndrome

The heme catabolite bilirubin has anti-inflammatory, anti-oxidative and anti-mutagenic effects and its relation to colorectal cancer (CRC) risk is currently under evaluation. Although the main metabolic steps of bilirubin metabolism, including the formation of stercobilin and urobilin, take place in the human gastrointestinal tract, potential interactions with the human gut microbiota are unexplored. This study investigated, whether gut microbiota composition is altered in Gilbert’s Syndrome (GS), a mild form of chronically elevated serum unconjugated bilirubin (UCB) compared to matched controls. Potential differences in the incidence of CRC-associated bacterial species in GS were also assessed. To this end, a secondary investigation of the BILIHEALTH study was performed, assessing 45 adults with elevated UCB levels (GS) against 45 age- and sex-matched controls (C). Fecal microbiota analysis was performed using 16S rRNA gene sequencing. No association between mildly increased UCB and the composition of the gut microbiota in this healthy cohort was found. The alpha and beta diversity did not differ between C and GS and both groups showed a typical representation of the known dominant phyla. Furthermore, no difference in abundance of Firmicutes and Proteobacteria, which have been associated with the mucosa of CRC patients were observed between the groups. A sequence related to the Christensenella minuta strain YIT 12065 was identified with a weak association value of 0.521 as an indicator species in the GS group. This strain has been previously associated with a lower body mass index, which is typical for the GS phenotype. Overall, sex was the only driver for an identifiable difference in the study groups, as demonstrated by a greater bacterial diversity in women. After adjusting for confounding factors and multiple testing, we can conclude that the GS phenotype does not affect the composition of the human gut microbiota in this generally healthy study group.

scholarly journals Phylogenetic barriers to horizontal transfer of antimicrobial peptide resistance genes in the human gut microbiota

2018 ◽  
Author(s):  
Bálint Kintses ◽  
Orsolya Méhi ◽  
Eszter Ari ◽  
Mónika Számel ◽  
Ádám Györkei ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Gut Microbiota ◽  
Resistance Genes ◽  
Gut Microbiome ◽  
Horizontal Transfer ◽  
Bacterial Species ◽  
Antibiotic Resistance Genes ◽  
Genetic Exchange ◽  
Human Gut ◽  
Human Gut Microbiota

AbstractThe human gut microbiota has adapted to the presence of antimicrobial peptides (AMPs) that are ancient components of immune defence. Despite important medical relevance, it has remained unclear whether AMP resistance genes in the gut microbiome are available for genetic exchange between bacterial species. Here we show that AMP- and antibiotic-resistance genes differ in their mobilization patterns and functional compatibilities with new bacterial hosts. First, whereas AMP resistance genes are widespread in the gut microbiome, their rate of horizontal transfer is lower than that of antibiotic resistance genes. Second, gut microbiota culturing and functional metagenomics revealed that AMP resistance genes originating from phylogenetically distant bacteria only have a limited potential to confer resistance inEscherichia coli, an intrinsically susceptible species. Third, the phenotypic impact of acquired AMP resistance genes heavily depends on the genetic background of the recipient bacteria. Taken together, functional compatibility with the new bacterial host emerges as a key factor limiting the genetic exchange of AMP resistance genes. Finally, our results suggest that AMPs induce highly specific changes in the composition of the human microbiota with implications for disease risks.

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