Accordingly, compared to the highest-acetate-producing strain ENT3, S100a8, part of fecal calprotectin and serving as a biomarker for colitis, was shown to be significantly upregulated in the PBS and Sc controls, and there was a trend towards increased expression in the non-acetate-producing SDH1 strain and the ENT strain. The gene discussed is S100A8; the disease is colitis.