The fecal acetate level correlated negatively with the protein intake (r = −0.285, p = 0.032), insulin level (r = −0.301, p = 0.024), and the HOMA-IR value (r = −0.284, p = 0.034), and it correlated positively with the γ-GTP level (r = 0.288, p = 0.030) in the T2DM patients, correlations that were not apparent in the control subjects. The gene discussed is INS; the disease is type 2 diabetes mellitus.