NFKB1 and Alzheimer disease: Therefore, to understand the role of commensal gut Bifidobacteria in the occurrence of AD, we isolated anti-inflammatory Bifidobacterium longum NK46, which suppressed human gut microbiota LPS production and NF-κB activation in LPS-stimulated microglial BV-2 cells, from healthy human fecal microbiota and examined whether NK46 could alleviate cognitive decline and gut microbiota dysbiosis in 5XFAD-Tg and aged mice.