GCG and Alzheimer disease: In AD group, the Firmicutes, Actinobacteria showed a significant decrease at the phylum level, and the Fusobacteria, Enterococcus, Proteus showed an increase compare with control group, while MG1363-pMG36e-GLP-1 obviously reduced the pathogen Fusobacterium (at Genus) (p < 0.05).