Abstract:This study aims to preliminarily explore the effects of Enterococcus faecium R-026 and Bacillus subtilis R-179 on 1-methyl-4-phenyl-1，2，3，6-tetrahydropyridine（MPTP）-induced Parkinson′s disease（PD）mice，with a focus on their impact on the intestinal microbiota of mice. PD mouse models were established by intraperitoneal injection of MPTP. After administration of a combination of E. faecium and B. subtilis （B. subtilis R-179 and E. faecium R-026，BE），serum-related indicators were measured，and high-throughput sequencing analysis of 16S rDNA was used to detect changes in the abundance of intestinal microbiota in each group of mice. Behavioral results showed that compared with the model group （MPTP group），the BE group had shorter pole-climbing time，higher hanging test scores，and a significantly increased total distance traveled in the open field test within 5 minutes. Biochemical index results indicated that the BE group had higher activities of superoxide dismutase （SOD） and catalase （CAT），higher glutathione （GSH） content，lower malondialdehyde （MDA）content in serum，and higher dopamine （DA） content in brain tissue compared with the MPTP group. Western blot results showed that after probiotic treatment，the protein expression levels of hemeoxygenase-1（HO-1）and nuclear factor erythroid 2-related factor 2 （Nrf2） in the brain tissue of BE group mice were increased.16S rDNA results showed that compared with the blank group （Con group），the abundances of Proteobacteria，Bacteroidetes，and Verrucomicrobia were significantly increased in PD mice，while the abundances of Actinobacteria， Patescibacteria， Campylobacterota， Cyanobacteria，and Deferribacteres were significantly decreased. Probiotic intervention corrected the above changes in the phylum-level intestinal microbiota of PD mice.The combination of E. faecium and B. subtilis has a significant therapeutic effect on MPTP-induced PD mice，and the mechanism may be related to antioxidant effects and the synergistic action of intestinal microbiota.