Faecalibacterium prausnitzii
Faecalibacterium prausnitzii is one of the most abundant bacteria in a healthy adult gut and a prolific producer of butyrate from dietary fiber. It belongs to the Firmicutes phylum.
Because it makes butyrate that fuels the cells lining your colon, this species is frequently studied as a marker of a well-nourished, balanced gut. Lower levels have been observed alongside several gut and inflammatory conditions, making it one of the most-watched single species.
A higher share of F. prausnitzii is generally framed positively, reflecting a strong presence of a key fiber-fermenting, butyrate-making microbe. Since this is a relative snapshot of one sample, it is a supportive signal rather than a diagnosis.
A lower share can be seen with lower-fiber diets or alongside some gut conditions in research, though a single low reading does not diagnose anything on its own.
The main lever people are pointed toward is eating more and more varied fiber, which feeds this species. Given how young this science is, treat your level as a trend to support over time and discuss meaningful changes with a clinician.
Sources
Educational context only, not medical advice or a diagnosis. Reference ranges vary by lab, age and sex; always discuss your results with a clinician.