Oral microbiota dysbiosis and increased inflammatory cytokines with different stroke subtypes

Abstract

Abstract Background: The possible correlation between oral microbiota dysbiosisand acute ischemic stroke, regarding different pathogenesis and stroke severity, remains unclear. Therefore, this study aimed to identify the specific microbiota for different subtypes of stroke to discover the underlying risk factors for ischemic stroke, which is of important clinical research value. Methods:Oral microbiota communities from 162 stroke patients and 62 stroke-free controls were prospectively assessed by sequencing the V3–V4 region of the 16S DNA gene. Demographic and clinical data were obtained for both groups. Triglycerides, total cholesterol, low-density lipoprotein, homocysteine, high-sensitivity C-reactive protein, SLCO1B1, APOE, CYP2C19, IL6, IL8, IL1β, TNF-α, and sCD40L were measured, and their relationship with oral microbiota was analyzed. Cranial magnetic resonance and carotid artery ultrasound were performed for both groups within seven days of admission. Results: IL6, IL8, IL1β, TNF-α, and sCD40L were significantly higher in stroke patients than in controls. Although the oral microbiota of the stroke and control groups were similar in diversity and structure, that of the severe stroke (National Institutes of Health Stroke Scale score > 5) and cardioembolic stroke subgroups differed from those of the control group. Linear discriminant analysis effect size analysis showed that Megasphaera, Prevotella_1, Clostridia, Selenomonas_3, Prevotella_6, and Dialister were mainly enriched in the severe stroke subgroup. Prevotella_6, Staphylococcus, Staphylococcaceae, and Peptostreptococcus were significantly enriched in the cardioembolic stroke subgroup. Spearman correlation analysis revealed that IL6, IL8, IL1β, TNF-α, and sCD40L were significantly correlated with Peptostreptococcus, Staphylococcus, Selenomonas, Megasphaera, and other bacteria (p < 0.01; p < 0.05). Conclusions: The oral microbiota in stroke patients were not significantly different from that in the stroke-free controls. However, certain stroke subgroups, such as the severe or cardioembolic stroke subgroups, exhibited significant oral microbiota dysbiosis, which was associated with elevated inflammatory cytokines.