Microbiota dysbiosis and functional outcome in acute ischemic stroke patients

Abstract

Currently, few studies are reported on the composition of microbiota in stroke patients and the association with stroke prognosis. This study investigated the differing microbiota composition in stroke patients and confirmed the association of microbiota composition with poor functional outcome. Between January of 2018 and December of 2019, 198 patients with acute cerebral infarction were included in this study. For the case–control study, age and sex-matched normal healthy subjects (n = 200) were included when receiving their health screening examinations. We isolated bacterial extracellular membrane vesicles and extracted DNA from blood samples. Taxonomic assignments were performed by using the sequence reads of 16S rRNA genes following blood microbiota analysis. Statistical analysis was conducted appropriately by using Statistical Analysis System software. The mean age of the stroke patients were 63.7 ± 12.5 years, and the male sex was 58.5%. Of the total enrolled patients, poor functional outcome (modified Rankin Score ≥ 3) was noted in 19.7%. The principal component analysis of microbiota composition revealed significant differences between healthy control subjects and stroke patients. At the genus level, Aerococcaceae(f), ZB2(c), TM7-1(c), and Flavobacterium were significantly increased in stroke patients compared to the healthy controls, whereas Mucispirillum, rc4-4, Akkermansia, Clostridiales(o), Lactobacillus, and Stenotrophomonas were decreased considerably. For the functional outcome after ischemic stroke, Anaerococcus, Blautia, Dialister, Aerococcaceae(f), Propionibacterium, Microbacteriaceae(f), and Rothia were enriched in the group with good outcomes, whereas Ruminococcaceae(f) and Prevotella were enriched in the group with poor outcome. There was apparent dysbiosis of blood microbiota in patients with acute ischemic stroke compared to healthy people. Ruminococcaceae(f) and Prevotella were elevated in stroke patients with poor functional outcome.

Prevotella species as oral residents and infectious agents with potential impact on systemic conditions

“…Some fragmentary information is available on the involvement of Prevotella organisms in vascular conditions in the intracranial region. Regarding ischemic stroke, the genus Prevotella was found to be enriched in the patient group with poor treatment outcome [ 228 ]. DNA of P. intermedia has been recovered from ruptured intracranial aneurysm walls [ 229 ] and in culture of cerebrospinal fluid from a patient of intracranial mycotic aneurysm [ 230 ].…”

Bacterial Signatures of Cerebral Thrombi in Large Vessel Occlusion Stroke

“…Bacteria in the thrombus and plasma samples were similar, and 46.7% of thrombus bacteria may originate from plasma samples based on the FEAST algorithm. Previous studies have also detected bacterial fragments in the plasma of healthy individuals ( 28 ) and ischemic stroke patients ( 29 ), of which several bacteria were culturable ( 28 ). However, the sources of the circulating bacteria were uncertain in these previous investigations.…”

Intestinal Flora Composition Determines Microglia Activation and Improves Epileptic Episode Progress

“…16S rDNA sequencing of intestinal microorganisms showed that f_Ruminococcaceae abundance increased most significantly in the immune-tolerant group ( Figure 3E ). This flora is closely related to nervous system diseases, such as Alzheimer’s disease, depression, and stroke ( Chang et al., 2021 ; Chen et al., 2021 ; Cuervo-Zanatta et al., 2021 ). Ruminococcus helps inhibit the translocation of bacterial products (e.g., LPS) into the blood, which may activate the Toll-like receptor 4 (TLR4), stimulate inflammatory responses, and secrete proinflammatory cytokines ( Shi et al., 2006 ; Cani et al., 2007 ).…”