Association between Apolipoprotein E genotype and the gut microbiome composition in humans and mice
AbstractApolipoprotein E (APOE) genotype is the strongest prevalent genetic risk factor for Alzheimer’s disease. Numerous studies have provided insights into the pathological mechanisms. However, a comprehensive understanding of the impact ofAPOEgenotype on microflora speciation and metabolism is completely lacking. The aim of this study was to investigate the association betweenAPOEgenotype and the gut microbiome composition in human andAPOE-targeted replacement (TR,APOE3andAPOE4) transgenic mice. Faecal microbiota amplicon sequencing from matched individuals with differentAPOEgenotypes revealed no significant differences in overall microbiota diversity (alpha or beta diversity) in group-aggregated humanAPOEgenotypes. However, several bacterial taxa showed significantly different relative abundance betweenAPOEgenotypes. Notably, we detected an association ofPrevotellaceaeandRuminococcaceaeand several butyrate-producing genera abundances withAPOEgenotypes. These findings were confirmed by comparing the gut microbiota ofAPOE-TR mice. Furthermore, metabolomic analysis of faecal water from murine samples detected significant differences in microbe-associated amino acids and short-chain fatty acids betweenAPOEgenotypes. Together, the findings indicate thatAPOEgenotype associated with specific gut microbiome profiles in both humans and inAPOE-TR mice. This suggests that the gut microbiome is worth further investigation as a potential therapeutic target to mitigate the deleterious impact of theAPOE4allele on cognitive decline and the prevention and treatment of AD.