In particular, T2DM patients who were not treated with statins had significantly higher plasma levels of GUDCA, GCA, TCDCA, GCDCA, HDCA, GDCA, CDCA, GLCA and DCA when compared with both T2DM patients treated with statins and non-diabetic subjects, regardless of the use of statins. The gene discussed is GNAT3; the disease is type 2 diabetes mellitus.