The gut microbiota-derived metabolites worsen through the destruction of the gut mucosal immune system, increased gut permeability (“leaky gut”), and altered bacterial translocation (Jiang et al., 2017), exacerbating systemic inflammatory responses (imbalance of Th17/Treg cells, interleukin [IL]-6 and IL-1β, interferon-gamma [IFN-γ], TNF-α, and TGF-β), which contribute to the adverse effects related to AD pathogenesis (Gasaly, de Vos & Hermoso, 2021; Hur et al., 2020; Yao & Yan, 2020). Here, IFNG is linked to Alzheimer disease.