Education as Risk Factor of Mild Cognitive Impairment: The Link to the Gut Microbiome

Abstract

Background With differences apparent in the gut microbiome in mild cognitive impairment (MCI) and dementia, and risk factors of dementia linked to alterations of the gut microbiome, the question remains if gut microbiome characteristics may mediate associations of education with MCI. Objectives We sought to examine potential mediation of the association of education and MCI by gut microbiome diversity or composition. Design Cross-sectional study. Setting Luxembourg, the Greater Region (surrounding areas in Belgium, France, Germany). Participants Control participants of the Luxembourg Parkinson’s Study. Measurements Gut microbiome composition, ascertained with 16S rRNA gene amplicon sequencing. Differential abundance, assessed across education groups (0–10, 11–16, 16+ years of education). Alpha diversity (Chao1, Shannon and inverse Simpson indices). Mediation analysis with effect decomposition was conducted with education as exposure, MCI as outcome and gut microbiome metrics as mediators. Results After exclusion of participants below 50, or with missing data, n=258 participants (n=58 MCI) were included (M [SD] Age=64.6 [8.3] years). Higher education (16+ years) was associated with MCI (Odds ratio natural direct effect=0.35 [95% CI 0.15–0.81]. Streptococcus and Lachnospiraceae -UCG-001 genera were more abundant in higher education. Conclusions Education is associated with gut microbiome composition and MCI risk without clear evidence for mediation. However, our results suggest signatures of the gut microbiome that have been identified previously in AD and MCI to be reflected in lower education and suggest education as important covariate in microbiome studies. Electronic Supplementary Material Supplementary material is available for this article at 10.14283/jpad.2024.19 and is accessible for authorized users.

Gut microbiome and major depressive disorder: insights from two-sample Mendelian randomization

“…Gut microbes are multifunctional, dynamic community, that participates in a range of physiological processes critical to host health, making important contributions to energy homeostasis, metabolism, intestinal epithelial health, immune activity, and neurodevelopment. Detrimental changes in the diversity and relative abundance of microbial taxa and species that make up the gut flora have been termed “gut dysbiosis” and have been linked to a variety of diseases, including inflammatory bowel disease, asthma, obesity, dementia, and autism [ 2 , 3 ]. The human gut microbiota is influenced by environmental and other factors, and it is noteworthy that the importance of the host genetic component in shaping the composition of an individual’s microbiome has also been demonstrated [ 4 ].…”