Curr Neuropharmacol. 2026 Jul 10. doi: 10.2174/011570159X468669260626223524. Online ahead of print.
ABSTRACT
BACKGROUND: Genetic evidence implicates the contribution of the gut-brain axis to neurodegenerative diseases (NDDs). Alterations in gut microbiota and inflammation are key pathophysiological contributors. Elucidating the genetic basis and the role of cytokines can provide insights into mechanisms linking gut microbial composition to neurodegeneration.
METHODS: Using aggregated statistics from five large-scale Genome-Wide Association Studies (GWAS) on Alzheimer’s disease, Parkinson’s disease, dementia with Lewy bodies, multiple sclerosis, and amyotrophic lateral sclerosis, bidirectional two-sample Mendelian Randomization (MR) was used to examine the associations. A two-step multivariable Mendelian randomization approach incorporates data from 91 cytokines to explore potential mediators.
RESULTS: The study reveals 18 positive and 17 negative effects between gut microbiota and NDDs, as well as 10 positive and 10 negative effects between cytokines and NDDs. Remarkably, mediation analysis identified a causal pathway, with evidence that plasma neurturin levels partially mediate the association from genus Ruminococcus2 to multiple sclerosis, with a mediation proportion of 19.19% (OR = 1.038, 95% CI = 1.001-1.086, P = 0.044). No pleiotropy or heterogeneity was detected.
DISCUSSION: These MR findings provide compelling evidence for a genetically anchored gutimmune-brain network in NDDs, with cytokines as intermediates. Bidirectional effects highlight disease-specific microbial signatures and inflammatory contexts. The Ruminococcus2-neurturin pathway in multiple sclerosis may offer mechanistic specificity, aligning with neurotrophic and anti-inflammatory signaling pathways.
CONCLUSION: This study emphasizes the importance of gut microbiota alterations in NDDs and explores inflammation’s partial intermediary role. The findings suggest potential targets for personalized neurodegeneration prevention strategies.
PMID:42460525 | DOI:10.2174/011570159X468669260626223524
