ACAT1 and ulcerative colitis: Furthermore, butyrate is oxidized in mitochondria by a series of five enzymes including the mitochondrial enzyme acetoacetyl CoA thiolase, and butyrate oxidation has been shown to be impaired in ulcerative colitis patients (Roediger et al., 1993; Ahmad et al., 2000; Santhanam et al., 2007) suggesting that butyrate plays an important role in TCA activity in colonocytes and therefore overall colon health.