Overview
Coprococcus eutactus is a strictly anaerobic, Gram-positive bacterium belonging to the family Lachnospiraceae within the phylum Firmicutes. It is a regular member of the healthy human gut microbiome, distinguished by its exceptional metabolic versatility in butyrate production. Research suggests that C. eutactus may play important roles in both metabolic and mental health, with its depletion consistently linked to depression across multiple independent studies. Its ability to produce neuroactive metabolites positions it as a key organism in gut-brain axis research.
Classification
C. eutactus belongs to the genus Coprococcus within the Lachnospiraceae family, a taxonomic group that includes many important short-chain fatty acid (SCFA) producers in the human gut. Related butyrate-producing species include Roseburia intestinalis and Eubacterium rectale. The genus Coprococcus contains several species, but C. eutactus is uniquely distinguished by its possession of dual butyrate synthesis pathways.
Key Characteristics
C. eutactus is the most metabolically versatile species within the Coprococcus genus, uniquely containing both the butyrate kinase (Buk) and butyryl-CoA:acetate-CoA transferase (But) gene pathways for butyrate synthesis. This dual pathway capability may allow it to produce butyrate under a wider range of gut conditions than species relying on a single pathway. Beyond SCFA production, C. eutactus produces DOPAC, a dopamine metabolite that may contribute to gut-brain axis signaling, as well as indolepropionic acid (IPA), a tryptophan-derived metabolite with neuroprotective, antidiabetic, and antioxidative properties. Population-level analyses have also identified positive correlations between Coprococcus species and circulating omega-3 polyunsaturated fatty acids.
Health Significance
The connection between C. eutactus and mental health represents one of the more compelling findings in gut-brain axis research. A meta-analysis across multiple cohorts found the Coprococcus genus, including C. eutactus, inversely associated with depression scores, with its DOPAC production pathway proposed as a potential mechanism. The species is also reduced in type 2 diabetes patients and inversely correlated with ileal Crohn's disease. Its association with the neuroprotective antioxidant IPA may suggest broader roles in neurological health beyond mood regulation. However, while observational associations are strong, interventional studies demonstrating that supplementation with C. eutactus can improve mental health outcomes are still needed to confirm causality.