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Updated: May 13, 2026

Microbiota Analysis Using Two-step PCR and Next-generation 16S rRNA Gene Sequencing
11:22

Microbiota Analysis Using Two-step PCR and Next-generation 16S rRNA Gene Sequencing

Published on: October 15, 2019

Bidirectional mediation between microbiota and immune system in Parkinson disease: A two-sample Mendelian

Taimei Qu1, Qiang Zhao2,3, Jiasheng Fang4

  • 1Department of Ultrasound, The Second Medical Center of Chinese PLA General Hospital, Beijing, China.

Medicine
|May 12, 2026
PubMed

Insights

This study used genetic data to link gut and skin microbes, immune cells, and inflammatory proteins to Parkinson disease (PD). Findings reveal causal pathways, suggesting the microbiota-immune axis is key in PD development.

Area of Science:

  • Genetics
  • Microbiology
  • Immunology
  • Neuroscience

Background:

  • Emerging evidence suggests a connection between the gut microbiome, skin microbiome, immune system, and Parkinson disease (PD).
  • The precise causal links and biological mechanisms underlying these associations remain largely undetermined.

Purpose of the Study:

  • To investigate the causal relationships between gut microbiota, skin microbiota, immune cell phenotypes, inflammatory proteins, and Parkinson disease (PD).
  • To explore potential mediating pathways in the "microbiota-immune-PD" axis using genetic data.

Main Methods:

  • A two-sample Mendelian randomization analysis was performed using genome-wide association study summary data.
  • Included were 473 gut microbial taxa, 150 skin microbial taxa, 731 immune cell phenotypes, and 91 inflammatory proteins.
  • Sensitivity and mediation analyses were conducted to ensure robustness and identify biological pathways.

Main Results:

  • Significant causal associations were found between 16 gut microbial taxa, 2 skin microbial taxa, 19 immune cell phenotypes, and 4 inflammatory proteins with PD.
  • Two-step mediation analyses identified "microbiota-immune-PD" and "immune-microbiota-PD" pathways.
  • Specific examples include mediation by HLA DR on myeloid dendritic cells and the bacterium Bifidobacterium adolescentis, with IL-18 showing substantial mediation via Lentimicrobiaceae.

Conclusions:

  • This study provides novel genetic evidence supporting the role of the microbiota-immune axis in Parkinson disease pathogenesis.
  • The findings highlight specific microbial taxa, immune cells, and inflammatory proteins as potential therapeutic targets for PD intervention.
Keywords:
Mendelian randomizationParkinson diseasegut microbiotaimmune cellsinflammatory proteinsmediation analysisskin microbiota

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