Inhibition of colorectal cancer in Alzheimer's disease is mediated by gut microbiota via induction of inflammatory tolerance

Epidemiological studies have revealed an inverse relationship between the incidence We aimed to determine whether the incidence of CRC is reduced in AD- like mice and whether gut microbiota confers resistance to tumorigenesis through inducing inflammatory tolerance using 16S ribosomal RNA gene sequencing and fecal microbiota transplantation (FMT). AD- like mice experienced a significantly decreased incidence of CRC tumorigenesis induced by azoxymethane-dextran sodium sulfate as evidenced by suppressed intestinal inflammation compared with control mice. However, FMT from age- matched control mice reversed the inhibitory effects on the tumorigenesis of CRC and inflammatory response in AD- like mice. The key bacterial genera in gut microbiota, including Prevotella, were increased in both the AD- like mice and in patients with amnestic mild cognitive impairment (aMCI) but were decreased in patients with mice. Imbalanced gut microbiota increased intestinal barrier permeability, which facil