Longevity & AgingAlzheimer's Amyloid Disrupts Gut Immunity and Drives Brain-Gut Immune Cell Migration
Researchers used single-cell RNA sequencing and flow cytometry to map the colonic immune landscape in the 5XFAD Alzheimer's mouse model. They found broad immune activation in the gut alongside a striking reduction in CXCR4-expressing antibody-secreting cells in the colon. Simultaneously, gut-origin CXCR4+ B cells and IgA+ plasma cells accumulated in the brain and dura mater, respectively. The AD brain showed elevated CXCL12, the chemokine that attracts CXCR4+ cells, suggesting gut immune cells are being redirected to the brain. Dietary supplementation with inulin prebiotic fiber partially reversed these changes, expanding colonic IgA+ cells, rescuing systemic regulatory T cell levels, reducing gut dysbiosis, and attenuating AD-associated frailty.
