This pilot prospective open-labeled, randomized, controlled trial was operated in patients with Parkinson’s disease to compare gut microbiome in negative and positive H. pylori infection. Successful eradication was defined as negative stool H. Pylori antigen. Gut microbiota was evaluated by 16S rDNA gene sequencing and subsequent bioinformatic analysis in both groups. MDS-UDPRS III-IV score, Levodopa equivalent daily dose and H&Y stage were assessed at week 8, 16, and 36. The GI function was quantified by using GIDS-PD. The primary outcome was the baseline-to-week 8 change in ON medication MDS-UPDRS motor scores. The diversity of gut microbiota was also interpreted in each group. 

We compared the fecal microbiome of five PD patients with H. pylori-positive and five PD patients with H. pylori-negative as control subjects before and after H. pylori eradication therapy. Regarding H. pylori eradication, there was significant reduction in MDS-UPDRS-III scores after treatment (p < 0.029). According to microbial diversity in fecal specimen, the analysis demonstrated that both H. pylori-negative and H. pylori-positive specimens are clustered in each group.

The clustered difference of gut microbiome in H. pylori negative and positive group showed the effect on clinical motor symptoms in PD.