Lachnospiraceae

A family within the Firmicutes phylum (order Clostridiales, formerly Clostridium cluster XIVa) that serves as a sentinel indicator of gut health -- its depletion is the single most consistent microbiome signature across nearly every disease represented in this wiki. The family includes major SCFA-producing genera: roseburia, blautia, Coprococcus, Dorea, Anaerostipes, and Butyrivibrio.

Role as a Dysbiosis Sentinel

Lachnospiraceae depletion recurs across an extraordinary range of diseases, making it a universal marker of dysbiosis:

- Multiple sclerosis: depleted in MS patients; loss reduces anti-inflammatory SCFA signaling to the CNS via the gut brain axis.
- Parkinson's disease: consistently reduced alongside Prevotellaceae; their loss increases gut permeability and facilitates alpha-synuclein propagation [pendergrass 2026 microbial metallomics parkinsons ferroptosis].
- Inflammatory bowel disease: depleted in both Crohn's disease and ulcerative colitis; inversely correlated with disease activity.
- Colorectal cancer: depleted in CRC patients, with lifestyle factors (smoking, alcohol) further reducing abundance [hoang 2023 dysbiotic microbiome crc lifestyles metabolic]. Ketogenic diet intervention restores Lachnospiraceae NK4A136 [gao 2026 ketogenic diet fxr nfkb crc].
- Cardiovascular disease: 12 of 23 differentially abundant taxa in CAD belonged to Lachnospiraceae, including Anaerosporobacter and NK4B4 group [toya 2020 coronary artery disease altered gut microbiome]. Butyrate-producing members depleted in ACVD [jie 2017 gut microbiome acvd].
- Autism spectrum disorder: depleted in ASD children, correlating with reduced SCFA levels.
- Type 2 diabetes: reduced in T2D; inversely correlated with HbA1c.

SCFA Production

- The family collectively produces butyrate, acetate, and propionate from dietary fiber fermentation.
- Butyrate production via the butyryl-CoA:acetate CoA-transferase pathway is the dominant route.
- Butyrate from Lachnospiraceae members acts as:
- The primary energy source for colonocytes (70% of energy).
- An HDAC inhibitor promoting Treg differentiation and anti-inflammatory cytokine production.
- A maintainer of epithelial hypoxia that preserves the anaerobic niche for beneficial obligate anaerobes.
- Loss of Lachnospiraceae SCFA output triggers a vicious cycle: reduced butyrate -> impaired barrier -> oxygen leak into lumen -> expansion of facultative anaerobic enterobacteriaceae -> further displacement of obligate anaerobes.

Metal Sensitivity

- Lachnospiraceae members are sensitive to heavy metal stress. Cadmium, lead, and mercury exposure depletes the family disproportionately compared to metal-tolerant taxa.
- Iron-sulfur cluster enzymes required for butyrate production are vulnerable to disruption by toxic metals that compete for iron binding sites.
- Siderophore-producing enterobacteriaceae outcompete Lachnospiraceae for iron under metal-stressed conditions, compounding the depletion.
- This metal sensitivity positions Lachnospiraceae as a biomarker for metal-induced dysbiosis within the gut metal microbiome framework.

Key Member Genera

| Genus | Key Function |
|-------|-------------|
| roseburia | Major butyrate producer; R. intestinalis, R. hominis |
| blautia | SCFA producer; bile acid metabolism |
| Coprococcus | Butyrate producer; depleted in depression |
| Dorea | SCFA producer; some species enriched in disease |
| Anaerostipes | Lactate-to-butyrate converter; metabolic cross-feeder |
| Butyrivibrio | Fiber fermenter; bile acid transformer |

Connections

- roseburia -- key butyrate-producing member genus; depleted across diseases
- blautia -- SCFA and bile acid metabolizing member genus
- faecalibacterium prausnitzii -- complementary butyrate producer; co-depleted in disease
- clostridium -- former Clostridium cluster XIVa members now classified here
- enterobacteriaceae -- inversely correlated; Enterobacteriaceae bloom when Lachnospiraceae deplete
- multiple sclerosis -- depletion impairs SCFA-mediated immune tolerance
- parkinsons disease -- loss linked to gut permeability and alpha-synuclein propagation
- colorectal cancer -- depletion reduces anti-tumorigenic butyrate; lifestyle factors compound loss
- cardiovascular disease -- 12/23 differentially abundant CAD taxa from this family
- iron -- Fe-S cluster enzymes vulnerable to metal competition
- dysbiosis -- the most universally depleted family across disease states
- gut metal microbiome -- metal sensitivity makes Lachnospiraceae a sentinel for environmental exposure
- inflammation -- butyrate loss removes HDAC-mediated anti-inflammatory brake