Moreover, it has been reported that epsilon-4 allele Apolipoprotein E (ApoE4) carriers, which are at much higher risk to develop AD [3, 29, 68], display a lower abundance of protective SCFA-producing bacteria such as Ruminococcaceae, making them more vulnerable to loss of intestinal integrity and increased permeability [116]. The gene discussed is APOE; the disease is Alzheimer disease.