The Second Opening: The Fecal Lipid Biomarkers

The 2020 paper by Sistiaga and colleagues represents the most methodologically innovative contribution to the Paisley story, and it merits careful attention because of what it adds — and what it honestly acknowledges.

The paper reported the application of fecal lipid biomarker analysis to Paisley coprolites.

The specific biomarkers analyzed were fecal stanols — compounds produced by the bacterial reduction of sterols in the intestine, with different mammals producing different characteristic stanol profiles.

The human-specific stanol profile — dominated by coprostanol, 5β-cholestan-3β-ol — is well-documented in fresh and ancient human fecal material and has been used extensively as a tracer for human sewage in environmental archaeology.