20 of these 119 genera were initially identified as genetically associated with AD, and three genera (Eubacterium fissicatena as a protective factor, Collinsella, and Veillonella as a risk factor) were independently significant and notably, the Collinsella genera positively correlated with the APOE rs429358 risk allele, suggesting that proinflammatory gut microbiome could promote AD through interactions with APOE [52]. This evidence concerns the gene APOE and Alzheimer disease.