Butyricimonas

Role in Gut Ecosystem#

One of the few Bacteroidetes members that produces significant butyrate, placing it in an unusual metabolic niche—most Bacteroidetes produce acetate, propionate, or succinate rather than butyrate.

Butyrate production supports colonocyte energy metabolism, tight junction protein expression, and Treg differentiation via HDAC inhibition and GPR109A signaling. Contributes to colonization resistance as part of the diverse anaerobic community that prevents pathogen expansion. Name derives from "butyric acid" (butyrici-) and "unit" (monas), reflecting its defining metabolic feature.

Multiple Sclerosis—Key Depleted Taxon#

Decreased in MS patients in the landmark Jangi 2016 study, which established the foundational MS-microbiome connection.^{[1]Alterations of the human gut microbiome in multiple sclerosisSushrut Jangi, Roopali Gandhi, Laura M. Cox et al. · 2016Open reference 1 ↓}

Butyricimonas abundance showed negative correlations with pro-inflammatory gene expression in circulating T cells and monocytes, including genes involved in dendritic cell maturation, interferon signaling, and NF-kB Signaling Pathway signaling.^{[1]Alterations of the human gut microbiome in multiple sclerosisSushrut Jangi, Roopali Gandhi, Laura M. Cox et al. · 2016Open reference 1 ↓}

This is the inverse of the pattern seen with Methanobrevibacter and Akkermansia muciniphila, which were increased in MS and positively correlated with these inflammatory pathways.^{[1]Alterations of the human gut microbiome in multiple sclerosisSushrut Jangi, Roopali Gandhi, Laura M. Cox et al. · 2016Open reference 1 ↓}

Higher baseline abundance in MS patients reported in the Troci 2022 study (as part of broader Bacteroidetes expansion), illustrating study-to-study variability.^{[2]B-cell-depletion reverses dysbiosis of the microbiome in multiple sclerosis patientsAlba Troci, Olga Zimmermann, Daniela Esser et al. · 2022Open reference 2 ↓}

Dietary intake patterns strongly modulate Butyricimonas abundance in MS cohorts, suggesting responsiveness to nutritional interventions.^{[3]Feeding the gut microbiome: impact on multiple sclerosisMatteo Bronzini, Alessandro Maglione, Rachele Rosso et al. · 2023Open reference 3 ↓}

Mechanistic Significance in MS#

The Jangi 2016 findings position Butyricimonas as a key anti-inflammatory species in MS.

Its negative correlation with interferon signaling genes suggests that butyrate from Butyricimonas may suppress the type I IFN response that drives MS pathology. The anti-inflammatory effect parallels that of Faecalibacterium prausnitzii but from within the Bacteroidetes phylum, providing taxonomic diversity in the butyrate-producing consortium.

Loss of Butyricimonas in MS may contribute to the reduced serum butyric acid levels and increased gut permeability documented in MS patients.