A Gram-positive, obligate anaerobic genus within the Lachnospiraceae family (Firmicutes phylum). Dorea occupies a mixed role in the gut ecosystem -- while it is a core member of the healthy human microbiome, several species are consistently enriched in autoimmune and neurological conditions, particularly multiple sclerosis, making it a potential disease biomarker rather than a straightforwardly beneficial commensal.
Role in Gut Ecosystem
- Part of the Lachnospiraceae family, one of the most abundant bacterial families in the human colon, involved in complex carbohydrate fermentation.
- D. formicigenerans is the best-characterized species; it produces formate as a primary metabolic end-product, distinguishing it from butyrate-producing relatives like Roseburia and coprococcus.
- D. longicatena produces hydrogen gas (H2), which can feed hydrogenotrophic organisms including methanobrevibacter and sulfate-reducing bacteria.
- Also produces acetate and minor amounts of other short chain fatty acids.
Disease Associations
Multiple Sclerosis
- Consistently enriched in MS patients, particularly during relapse phases, alongside Blautia [radojevic 2023 microbiome gut brain axis ms].
- In the Saresella 2020 study, Dorea was decreased in SPMS compared to RRMS, suggesting it may track with active inflammatory disease rather than progressive neurodegeneration [saresella 2020 fatty acids dysbiosis inflammation ms].
- Atrial fibrillation causally affects Dorea abundance in bidirectional MR analysis, indicating that cardiovascular pathology can alter this genus [dai 2024 gut microbiota cvd bidirectional mr].
Autism Spectrum Disorder
- Increased in autism spectrum disorder youth across multiple observational reviews in the Romano 2023 umbrella review [romano 2023 gut microbiome children mental health umbrella review].
- Part of the Lachnospiraceae enrichment pattern seen in ASD, contrasting with depletion of other family members like coprococcus.
Colorectal Cancer
- Identified as one of the 18 dominant bacterial genera in CRC patient stool (Sobhani 2011), though its specific enrichment or depletion pattern in CRC is less consistent than for Fusobacterium or peptostreptococcus [sobhani 2011 microbial dysbiosis colorectal cancer].
Inflammatory Bowel Disease
- MR evidence suggests causal associations between Dorea and IBD risk, though directionality varies by study and IBD subtype [zhang 2021 causal direction microbiota ibd mr].
Key Metabolites
- Formate -- primary fermentation product of D. formicigenerans; substrate for other gut microbes
- Hydrogen gas (H2) -- produced by D. longicatena; feeds methanogens and sulfate reducers
- Acetate -- secondary fermentation product
Mechanistic Considerations
- The enrichment of Dorea in MS may relate to its role in H2 production, which supports methane-producing methanobrevibacter -- also elevated in MS.
- Formate production may influence one-carbon metabolism pathways relevant to immune cell proliferation and epigenetic regulation.
- As a Lachnospiraceae member that does not produce butyrate, Dorea enrichment in disease may reflect competitive displacement of butyrate-producing relatives within the same ecological niche.
Connections
- multiple sclerosis -- enriched in MS, particularly during relapse; potential biomarker
- autism spectrum disorder -- consistently elevated in ASD observational studies
- methanobrevibacter -- H2 cross-feeding relationship; both elevated in MS
- coprococcus -- Lachnospiraceae relative; shows opposite disease associations (depleted in disease)
- cardiovascular disease -- abundance causally affected by atrial fibrillation
- short chain fatty acids -- formate and acetate producer, but notably not butyrate
- dysbiosis -- enrichment pattern distinguishes it from depleted beneficial Lachnospiraceae
- inflammation -- association with active inflammatory phases in MS