Unveiling the negative association of Faecalibacterium prausnitzii with ischemic stroke severity, impaired prognosis and pro-inflammatory markers

The correlation between acute ischemic stroke (AIS) and gut microbiota has opened a promising avenue for improving stroke prognosis through the utilization of specific gut bacterial species. This study aimed to identify gut bacterial species in AIS patients and their correlation with stroke severity, 3-month prognosis, and inflammatory markers. Methods : We enrolled 59 AIS patients (from June 2021 to July 2022) and 31 age-matched controls with similar cerebrovascular risk profiles but no stroke history. Fecal samples were analyzed using 16 S rDNA V3–V4 sequencing to assess α and β diversity and identify significant microbiota differences. AIS cases were categorized based on the National Institute of Health Stroke Scale (NIHSS) scores and 3-month modified Rankin Scale (mRS) scores. Subgroup analyses were performed, and correlation analysis was used to examine associations between flora abundance, inflammatory markers and stroke outcome. Significant differences in β-diversity were observed between case and control groups ( P  < 0.01). Bacteroides dominated AIS samples, while Clostridia, Lachnospirales, Lachnospiraceae, Ruminococcaceae, Faecalibacterium, and Faecalibacterium prausnitzii were prominent in controls. Faecalibacterium and Faecalibacterium prausnitzii were significantly reduced in non-minor stroke and 3-month poor prognosis groups compared to controls, while this difference was less pronounced in patients with minor stroke and 3-month good prognosis. Both Faecalibacterium and Faecalibacterium prausnitzii were negatively correlated with the NIHSS score on admission ( r  = −0.48, −0.48, P  < 0.01) and 3-month mRS score ( r  = −0.48, −0.44, P  < 0.01). Additionally, they showed negative correlations with pro-inflammatory factors and positive correlations with anti-inflammatory factors (both P  < 0.01). Faecalibacterium prausnitzii is negatively associated with stroke severity, impaired prognosis, and pro-inflammatory markers, highlighting its potential application in AIS treatments.