RESUMO
Alzheimer's disease (AD) is the most common form of dementia. Besides its cognitive phenotype, AD leads to crucial changes in gut microbiome composition in model mice and in patients, but the reported data are still highly inconsistent. Therefore, we investigated chronic effects of AD-characteristic neurotoxic amyloid-ß (Aß) peptides as provided by transgenic overexpression (5xFAD mouse model) and acute effects due to oral application of Aß on gut microbes. Astonishingly, one-time feeding of wild type mice with Aß42 provoked immediate changes in gut microbiome composition (ß diversity) as compared to controls. Such obvious changes were not observed when comparing 5xFAD mice with wild type littermates. However, acute as well as chronic exposure to Aß significantly affected the abundance of numerous individual operational taxonomic units. This provides first evidence that acute in vivo exposure to Aß results in a shift in the enteric microbiome. Furthermore, we suggest that chronic exposure to Aß might trigger an adaptive response of gut microbiota which could thereby result in dysbiosis in model mice but also in human patients.
