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Oral microbiome dysbiosis in cryptogenic ischemic stroke patients with high-risk patent foramen ovale

Muhammed Manzoor1, Jaakko Leskelä2, Milla Pietiäinen2,3

  • 1Department of Oral and Maxillofacial Diseases, University of Helsinki, PO Box 63, 00014, Helsinki, Finland. muhammed.allippara@helsinki.fi.

Scientific Reports
|April 4, 2025
PubMed

Insights

Patent foramen ovale (PFO), a common heart defect, is linked to cryptogenic ischemic stroke (CIS). Oral microbiome differences were found in CIS patients with high-risk PFO, suggesting a potential role in stroke development.

Area of Science:

  • Cardiology
  • Neurology
  • Microbiome Research

Background:

  • Patent foramen ovale (PFO) is the most common congenital heart defect, often linked to cryptogenic ischemic stroke (CIS) via paradoxical embolism.
  • The role of the oral microbiome in PFO-associated CIS remains unclear, representing a gap in understanding stroke etiology.

Purpose of the Study:

  • To investigate differences in the oral microbiome between young-onset CIS patients with and without high-risk PFO.
  • To compare oral microbiomes of stroke patients with high-risk PFO to stroke-free controls with high-risk PFO.

Main Methods:

  • Saliva metagenomes were analyzed from young-onset CIS patients with high-risk PFO (n=52) and without PFO (n=52).
  • Age- and sex-matched stroke-free controls with high-risk PFO (n=16) were included for comparison.
  • Beta diversity analysis was performed to assess microbial community differences.

Main Results:

  • Significant differences in oral microbiome beta diversity were observed between patients with high-risk PFO and controls with high-risk PFO.
  • The phylum Ascomycota and class Saccharomycetes were more abundant in CIS patients with high-risk PFO compared to those without PFO.
  • Lactococcus abundance, including L. raffinolactis and L. cremoris, was higher in stroke-free controls with high-risk PFO than in CIS patients with high-risk PFO.

Conclusions:

  • Oral dysbiosis, characterized by specific microbial shifts, may be associated with patent foramen ovale in cryptogenic ischemic stroke.
  • The interplay between high-risk PFO and oral microbiome alterations presents a potential, under-recognized factor in CIS etiology.
  • Further research is needed to clarify the mechanisms and develop targeted interventions for PFO-associated CIS.
Keywords:
Cryptogenic ischemic strokeMetagenomic sequencingOral microbiomeParadoxical embolismPatent foramen ovaleSalivaStroke

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