Bacteroides genus is associated with lower executive function in cognitively unimpaired participants

Vitamin B1, B6, and B12 deficiencies are associated with increased prevalence of dementia due to Alzheimer’s disease (AD). Clinical trials suggest that vitamin supplementation may improve cognitive function, however the mechanisms that link these factors remain unknown. A site of vitamin metabolism and synthesis is the gut microbiome, which is compositionally altered in AD. The gut microbiota’s role in perpetuating vitamin deficiencies and subsequent cognitive decline is unclear, so here we tested the hypothesis that lower abundances of vitamin B‐modulating microbes are linked to lower cognitive testing scores.