Elevated Lactobacillus salivarius and genus Akkermansia in fecal samples of Taiwanese patients with parkinson’s disease and diabetes mellitus

Recent advancements in non-invasive collection methods and technological innovations have significantly enhanced the analysis of human gut microbiota, which has become a key approach for understanding complex disease pathogenesis. Epidemiological studies and clinical trials have revealed intriguing connections between Parkinson's disease (PD) and diabetes mellitus (DM). In this study, microbial populations from fecal samples of patients with PD and DM were analyzed. The prospective cohorts included four groups: PD only (n = 32), DM only (n = 170), and concurrent PD and DM (n = 10), matched with healthy controls (n = 98) by age and comorbidities. Fecal samples underwent full-length (V1-V9) 16 S rRNA sequencing analysis, and clinical and laboratory variables were collected. The results revealed an increased abundance of Lactobacillus salivarius in patients with PD (linear discriminant analysis [LDA] = 2.58, p value < 0.05) or DM (LDA = 2.20) compared to healthy controls. Similarly, an elevated abundance of the genus Akkermansia was observed in patients with PD (LDA = 4.39) or DM (LDA = 3.92). These findings suggest that gut microbiota alterations, particularly involving L. salivarius and Akkermansia spp., may play a role in the pathogenesis of PD and DM, warranting further investigation into their significance.