Apoe (encoding apolipoprotein E) knockout mice were fed a high-fat diet of medium-and long-chain triacylglycerols, which reduced the intestinal flora ratio of Firmicutes to Bacteroidetes, increased the abundance of short-chain fatty acid bacteria, and decreased the abundance of Ruminococcus torques, Ruminiclostridium 9, Catenibacterium, and Eubacterium fissicatena, thus alleviating atherosclerosis induced by a high-fat diet [29]. The gene discussed is APOE; the disease is atherosclerosis.