Figure 1.

The potential relationship between intestinal microbiome alterations, mucosal barrier dysfunction, neuroinflammation and the pathogenesis of AD. Dysbiosis of the intestinal microbiome facilitates intestinal barrier and BBB damage and the entry of pathogens and their products into the circulatory system. Pathogens and their products pass into the brain via damaged BBB, and may intensify inflammatory reactions, and induce amyloid aggregation and the occurrence of AD