Interactions between brain and bile acid ratio profiles predict baseline cognitive status

Alterations in the brain‐gut microbiome system are thought to play an important role in the development of neurodegenerative diseases. While the great majority of secreted primary bile acids (BAs) are reabsorbed in the ileum, about 5% are metabolized by gut microbes and reabsorbed. Alterations in secondary BAs metabolism associated with specific gut‐microbial species, and reflected in altered ratios of primary and secondary BAs have recently been linked with brain atrophy and cognitive decline. The aim of this study was to investigate whether interactions between brain‐derived morphometric phenotypes and BA profiles can predict baseline cognitive status (cognitively normal (CN), mild cognitive impairment (MCI), Dementia (AD)) or conversion status (MCI to AD).