A qPCR-based approach targeting the microbial gene marker nanA of mucin-degrading Akkermansia in Parkinson's disease.

BackgroundParkinson's disease (PD) is a multifactorial neurodegenerative disorder increasingly linked to gut microbiota alterations. However, despite advances in fecal microbiota profiling as a non-invasive approach to disease risk assessment, its clinical utility remains limited by a lack of functionally relevant microbial biomarkers.ObjectiveThis cross-sectional study aimed to identify a microbial gene marker reflecting metabolic potential associated with both the presence and severity of PD.MethodsFecal samples from patients with PD (n = 59) and healthy controls (n = 65) were analyzed by 16S rRNA sequencing to characterize taxonomic profiles. Quantitative PCR (qPCR) targeted the consensus sequence of the mucin-degrading nanA gene (nanAkk), a highly conserved within Akkermansia nan gene clusters. Differences in taxonomic composition and nanAkk abundance were examined, and correlations with clinical severity scores evaluated in the PD group.ResultsPatients with PD showed reduced abundance of short-chain fatty acid-producing taxa (Faecalibacterium, Blautia, and Anaerostipes) and increased levels of Akkermansia. Akkermansia abundance correlated positively with motor severity, including Hoehn-Yahr stage. Moreover, nanAkk levels also correlated positively with Hoehn-Yahr stage and were significantly elevated in PD patients compared with controls. Levels in the stage 4-5 group exceeded those in the stage 1-3 group (P = 0.0202), indicating a stage-related increase in mucin-degrading nanAkk abundance.ConclusionsWe have identified nanAkk as a microbial gene marker associated with both the presence and severity of PD. Our qPCR-based quantification shows potential as a non-invasive biomarker for disease stratification.