The subgingival microbiome in Alzheimer's disease, mild cognitive impairment and subjective cognitive decline

The aim of this prevalence case-control study was to test the hypothesis that there are dissimilarities in the subgingival microbial community composition among individuals with Alzheimer´s disease (AD), mild cognitive impairment (MCI), subjective cognitive decline (SCD) and cognitively healthy individuals. The study population was recruited from October 2013 to April 2017 and comprised 132 patients newly diagnosed with AD (n = 46), MCI (n = 40) or SCD (n = 46) and 63 cognitively healthy individuals. Subgingival bacterial communities were characterized by sequencing V3-V4 16S ribosomal RNA bacterial genes using the Illumina MiSeq platform.