OMM12, also called Oligo-MM12 or Oligo-Mouse-Microbiota, is a defined 12-strain murine intestinal bacterial community used to colonize germ-free mice for reproducible microbiome research. The community includes Lactobacillus reuteri I49, Enterococcus faecalis KB1, Blautia coccoides YL58, Clostridium innocuum I46, Flavonifractor plautii YL31, Clostridium clostridioforme YL32, Acutalibacter muris KB18, Bacteroides caecimuris I48, Muribaculum intestinale YL27, Bifidobacterium longum subsp. animalis YL2, Akkermansia muciniphila YL44, and Turicimonas muris YL45. It is used as a reduced, genome-characterized model of the mouse gut microbiota for colonization resistance, mucosal immunology, microbial ecology, host-microbiome metabolic cross-talk, and facility-to-facility reproducibility studies.
Taxonomy
| Taxon | Ontology ID | Functional Roles | Abundance |
|---|---|---|---|
| OMM12 bacterial strain consortium — ontology label: Bacteria | NCBITaxon:2 · TaxonMech · TraitMech | N/A | |
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Ecological Interactions
The graph shows only explicitly linked interaction participants. Community members without an asserted participant link are omitted; membership alone does not imply an interaction.
Double-Dose OMM12 Engraftment
A second frozen OMM12 inoculum application 72 h after the first improved establishment across the participating germ-free mouse facilities, including more reliable detection of the slow-colonizing Muribaculum intestinale YL27. This is a tested dosing-protocol improvement, not demonstrated biotic facilitation by one member. Some strains remained below fecal qPCR detection in some samples, and the facility cohorts were not a fully matched randomized comparison.
Biological Processes:
- interspecies interaction between organisms (GO:0044419 · PathwayMech)
The repeat application after 72 h improved reproducibility of OMM12 establishment, particularly YL27 detection, relative to the single-dose protocol. This supports a protocol-to-colonization effect in the studied facility cohorts, not guaranteed detection of every strain or isolation of the effects of dose, timing and gut redox.
Evidence
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PMID:31998276 - SUPPORT (IN_VIVO)"We show that a second application of the OMM12 strains after 72 h leads to a more stable community composition than a single application."
Colonization Resistance Against Salmonella
The 12-member OMM12 community provided colonization resistance against Salmonella enterica serovar Typhimurium in gnotobiotic mice, but less than a conventional complex microbiota. Conventional-like resistance belongs to the expanded version with three added facultative anaerobic bacteria, not to this 12-member community. The phenotype is retained without assigning a uniquely established competition mechanism.
Biological Processes:
- interspecies interaction between organisms (GO:0044419 · PathwayMech)
Evidence
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PMID:27869789 - SUPPORT (IN_VIVO)"provided colonization resistance against S. Tm infection, albeit not to the degree of a conventional complex microbiota."
Reproducible Multi-Strain Intestinal Colonization
OMM12 was established in multiple germ-free mouse facilities, with strain-resolved fecal 16S rRNA gene-copy qPCR monitoring. The repeat-dose protocol improved reproducibility and YL27 establishment, but some other strains were undetected in some samples and facility differences persisted. Gene-copy counts per volume of extracted DNA are not viable cell counts or uniformly fecal-mass-normalized abundance. Compositional reproducibility alone does not establish functional equivalence or increased pathogen resistance.
Biological Processes:
- multi-organism process (GO:0044419 · PathwayMech)
Evidence
-
PMID:31998276 - SUPPORT (IN_VIVO)"established in several germ-free mouse facilities world-wide"
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PMID:31998276 - SUPPORT (IN_VIVO)"Absolute abundance of each strain was determined by a strain-specific qPCR assay"
Associated Datasets
| Dataset | Type | Repository | Accession |
|---|---|---|---|
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Oligo-MM12 whole-genome sequence resource
Genome announcement reporting high-quality whole-genome sequences for the Oligo-MM12 strains. |
GENOMICS | OTHER | PMID:29051233 |
Knowledge gaps & discussions (1)
KNOWLEDGE_GAP OPEN Which exact-system measurements distinguish the observed outcome from the proposed mechanism?
Preserve the positive repeat-dose establishment and 12-member resistance results. The protocol study compared staged facility cohorts and did not isolate a member-mediated redox mechanism; early colonizers lowering gut redox is proposed. Double inoculation improved YL27 detection while four other strains remained variably undetected. Facility-associated variation persisted, and compositional similarity was not a functional challenge assay. The 2016 primary abstract distinguishes OMM12 resistance from conventional-like resistance of the version expanded by three facultative anaerobes; full infection Methods were not inspected because the publisher provides subscription preview only. Remove the context-only colonization-to-resistance arrow rather than treating the two separate studies as a mediation experiment.
Attaches to: ecological_interactions#Double-Dose OMM12 Engraftment, ecological_interactions#Colonization Resistance Against Salmonella, ecological_interactions#Reproducible Multi-Strain Intestinal Colonization
Environmental Factors
| Factor | Value | Unit |
|---|---|---|
| Germ-free mouse host | Axenic mice colonized with OMM12 | N/A |
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| Facility reproducibility | Multiple germ-free mouse facilities | N/A |
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Growth Media
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