Gut microbiome profiling in early preclinical and clinical stages of Alzheimer's disease

Gut dysbiosis has been associated with different stages of Alzheimer's disease continuum, beginning from early preclinical stages characterized by normal cognition but abnormal values of brain biomarkers (such as amyloid-b) to clinical stages, as mild cognitive impairment (MCI). However, knowledge about the presence of distinct gut microbiota features that characterize these stages is limited. In this study, we profiled gut microbiome in a cohort of 50 individuals, which were classified based on cerebrospinal fluid amyloid-b values (amyloid-normal; n=21 and amyloid-pathology; n=29) or on clinical diagnosis criteria (cognitively normal; n=40 and mild cognitive impairment; n=10). Gut microbiota composition was compared across groups, while we also examined the discriminative performance of microbiota to classify groups of individuals. Findings will extend our knowledge for the implication of gut microbiome in different stages of AD and potentially could improve future gut-directed interventions to slow cognitive decline.