One of the most abundant gut bacteria in healthy adults, and a major supplier of butyrate to the colon. Explore its illustrative 3D model, human context, and sources.
F. prausnitzii is among the most abundant bacteria in the healthy adult gut, reported at 5 to 15% of the total bacterial population, and it is an important supplier of butyrate to the colonic lining. It is strictly anaerobic and extremely oxygen-sensitive: published work notes that faecalibacteria cannot withstand even a few minutes of exposure to ambient air, which makes the species difficult to culture and to study. Lower abundance has been observed alongside inflammatory bowel disease, colorectal cancer and type 2 diabetes, but those are associations reported in studies rather than demonstrated causes or treatments. Older studies used a broader species grouping: strain A2-165 is now classified as F. duncaniae. Historical abundance and association findings may include relatives separated by newer taxonomy.
A beneficial association does not establish safety, benefit or a treatment effect for any individual. The reported links between lower F. prausnitzii abundance and inflammatory or metabolic conditions are observed associations whose direction is not settled by the bundled evidence. This profile assigns no disease to this organism and no personal risk to any reader.
Original schematic 3D phenotype. The comparative-genome analysis describes cells as Gram-stain negative, non-motile, non-spore-forming and strictly anaerobic, so no flagella, capsule or endospore should be assigned. Note that this species stains Gram-negative but belongs to a Gram-positive lineage, so the envelope should not be drawn as a classical two-membrane Gram-negative wall without qualification, and the accompanying text should say which convention the diagram follows. Colours, dimensions, layer thicknesses and displayed arrangements are diagram choices, not a measured individual cell. Independent scientific review remains pending.
Source check: 2026-09-19. Educational content; independent scientific review remains pending.