The blood microbial community signatures in patients with acute ischemic stroke

While systemic inflammation and metabolic dysregulation contribute to acute ischemic stroke (AIS)development, the function of the peripheral blood microbiome, which reflects systemic states, remains unclear. This study aimed to characterize these blood microbial signatures and define their clinical relevance in AIS.

Blood microbiome profiles from 61 AIS patients and 54 controls were analyzed by 16S rRNA sequencing. Patients were stratified by baseline NIHSS scores and followed for 3-month outcomes to assess prognostic microbial signatures.

AIS patients exhibited a distinct blood microbiota profile compared to controls, characterized by reduced richness and significant structural changes. These alternations included a reduction of key commensal bacteria, such as Akkermansia, and an increase in opportunistic taxa like Meiothermus. Crucially, these microbial dysregulations were strongly correlated with host metabolic parameters, including blood glucose, homocysteine, and lipid levels. However, classification models based on the blood microbial signature failed to predict disease severity and 3-month neurological outcomes. In contrast, alterations in the blood microbiome demonstrated potential as an indicator of AIS severity (AUC = 0.733).

Our findings reveal that the blood microbiome in AIS is highly dysregulated, reflecting the host's systemic metabolic health. This strong association suggests circulating microbial signatures could play a role in stroke's pathophysiology, potentially influencing metabolic and inflammatory processes. As a result, analyzing these signatures could lead to the development of minimally invasive biomarkers for disease assessment and may also reveal novel therapeutic targets for managing systemic dysfunction in stroke patients.