Ruminococcus
Ruminococcus is a genus in the Firmicutes phylum whose members specialize in breaking down tough plant fibers, including resistant starch that many other microbes cannot access. This makes them important early players in fiber fermentation.
By unlocking hard-to-digest fibers, Ruminococcus helps feed the wider community, including butyrate producers downstream. Its share reflects, in part, how much complex plant fiber and resistant starch reaches your gut.
A higher share of Ruminococcus is generally viewed neutrally to favorably and can reflect a diet rich in complex fibers and resistant starch. Since the value is relative and the genus is diverse, a higher share is descriptive rather than a clear good sign, and not a diagnosis.
A lower share can accompany lower intake of complex plant fibers, though a single reading does not diagnose anything on its own.
A varied diet rich in whole plants and resistant starch is the usual general lever, rather than a target number. Given how young this science is, treat your level as part of a broader trend and interpret 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.