A defined two-member gnotobiotic mouse gut model pairing the human gut Bacteroidetes member Bacteroides thetaiotaomicron VPI-5482 with the human gut Firmicutes member Eubacterium rectale ATCC 33656. The model was used to examine niche specialization and metabolic interaction between dominant human gut phyla under controlled host and diet conditions. B. thetaiotaomicron expands polysaccharide utilization and host mucin glycan foraging in the presence of E. rectale, while E. rectale shifts away from glycan-degrading enzymes toward amino acid and sugar transport, glycolytic support, and butyrate generation from acetate.
Taxonomy
| Taxon | Ontology ID | Functional Roles | Abundance |
|---|---|---|---|
| Bacteroides thetaiotaomicron VPI-5482 | NCBITaxon:226186 |
PRIMARY_DEGRADER
CROSS_FEEDER
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N/A |
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| Eubacterium rectale ATCC 33656 | NCBITaxon:515619 |
SECONDARY_FERMENTER
CROSS_FEEDER
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N/A |
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Ecological Interactions
Bacteroides Polysaccharide Niche Expansion
NICHE_PARTITIONINGSource Taxon: Eubacterium rectale ATCC 33656
Target Taxon: Bacteroides thetaiotaomicron VPI-5482
Biological Processes:
- carbohydrate metabolic process (GO:0005975)
- biological process involved in interspecies interaction between organisms (GO:0044419)
Evidence
-
PMID:19321416 - SUPPORT (IN_VIVO)"B. thetaiotaomicron adapts to the presence of E. rectale by up-regulating a variety of loci specific for host-derived mucin glycans that E. rectale is unable to use"
Eubacterium Transport and Butyrate Shift
CROSS_FEEDINGSource Taxon: Bacteroides thetaiotaomicron VPI-5482
Target Taxon: Eubacterium rectale ATCC 33656
Metabolites: acetate (CHEBI:30089), butyrate (CHEBI:17968)
Biological Processes:
- butyrate biosynthetic process (GO:0019605)
- biological process involved in interspecies interaction between organisms (GO:0044419)
Evidence
-
PMID:19321416 - SUPPORT (IN_VIVO)"E. rectale adapts to B. thetaiotaomicron by decreasing production of its glycan-degrading enzymes, increasing expression of selected amino acid and sugar transporters"
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PMID:19321416 - SUPPORT (IN_VIVO)"generation of butyrate from acetate"
Cecal Short-Chain Fatty Acid Remodeling
CROSS_FEEDINGMetabolites: acetate (CHEBI:30089), butyrate (CHEBI:17968)
Biological Processes:
- fermentation (GO:0006113)
Evidence
-
PMID:19321416 - SUPPORT (IN_VIVO)"cecal acetate levels are significantly lower in cocolonized mice compared with B. thetaiotaomicron monoassociated animals"
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PMID:19321416 - SUPPORT (IN_VIVO)"cecal butyrate levels are similar in E. rectale mono- and biassociated animals"
Associated Datasets
| Dataset | Type | Repository | Accession |
|---|---|---|---|
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Exact-composition publication - Bacteroides thetaiotaomicron VPI-5482 and Eubacterium rectale ATCC 33656
Primary publication reporting the exact two-member gnotobiotic mouse model, with microbial transcriptomics, proteomics, metabolite assays, and host-response measurements. |
PHENOTYPE | OTHER | PMID:19321416 |
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Bacteroides-Eubacterium gnotobiotic mouse GEO datasets
GEO accessions deposited with the PNAS study for transcriptional profiling data from the gnotobiotic model. |
METATRANSCRIPTOME | OTHER | GSE14686; GSE14709; GSE14737 |
|
Eubacterium rectale ATCC 33656 complete genome project
NCBI BioProject for the E. rectale ATCC 33656 genome sequenced in the same study. |
GENOME | NCBI_BIOPROJECT | PRJNA29071 |
Environmental Factors
| Factor | Value | Unit |
|---|---|---|
| germ-free mouse host | Germ-free mice colonized with one or both human gut-derived strains. | N/A |
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| dietary perturbation | three dietary conditions | N/A |
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