Gut microbiota and stroke: New avenues to improve prevention and outcome

Hemorrhagic transformation in patients with large-artery atherosclerotic stroke is associated with the gut microbiota and lipopolysaccharide

JOURNAL/nrgr/04.03/01300535-202407000-00032/figure1/v/2023-11-20T171125Z/r/image-tiff

Hemorrhagic transformation is a major complication of large-artery atherosclerotic stroke (a major ischemic stroke subtype) that worsens outcomes and increases mortality. Disruption of the gut microbiota is an important feature of stroke, and some specific bacteria and bacterial metabolites may contribute to hemorrhagic transformation pathogenesis. We aimed to investigate the relationship between the gut microbiota and hemorrhagic transformation in large-artery atherosclerotic stroke. An observational retrospective study was conducted. From May 2020 to September 2021, blood and fecal samples were obtained upon admission from 32 patients with first-ever acute ischemic stroke and not undergoing intravenous thrombolysis or endovascular thrombectomy, as well as 16 healthy controls. Patients with stroke who developed hemorrhagic transformation (n = 15) were compared to those who did not develop hemorrhagic transformation (n = 17) and with healthy controls. The gut microbiota was assessed through 16S ribosomal ribonucleic acid sequencing. We also examined key components of the lipopolysaccharide pathway: lipopolysaccharide, lipopolysaccharide-binding protein, and soluble CD14. We observed that bacterial diversity was decreased in both the hemorrhagic transformation and non-hemorrhagic transformation group compared with the healthy controls. The patients with ischemic stroke who developed hemorrhagic transformation exhibited altered gut microbiota composition, in particular an increase in the relative abundance and diversity of members belonging to the Enterobacteriaceae family. Plasma lipopolysaccharide and lipopolysaccharide-binding protein levels were higher in the hemorrhagic transformation group compared with the non-hemorrhagic transformation group. lipopolysaccharide, lipopolysaccharide-binding protein, and soluble CD14 concentrations were associated with increased abundance of Enterobacteriaceae. Next, the role of the gut microbiota in hemorrhagic transformation was evaluated using an experimental stroke rat model. In this model, transplantation of the gut microbiota from hemorrhagic transformation rats into the recipient rats triggered higher plasma levels of lipopolysaccharide, lipopolysaccharide-binding protein, and soluble CD14. Taken together, our findings demonstrate a noticeable change in the gut microbiota and lipopolysaccharide-related inflammatory response in stroke patients with hemorrhagic transformation. This suggests that maintaining a balanced gut microbiota may be an important factor in preventing hemorrhagic transformation after stroke.

Multiomics profiling of the therapeutic effect of Dan-deng-tong-nao capsule on cerebral ischemia-reperfusion injury

BACKGROUND

Stroke is a complex physiological process associated with intestinal flora dysbiosis and metabolic disorders. Dan-deng-tong-nao capsule (DDTN) is a traditional Chinese medicine used clinically to treat cerebral ischemia-reperfusion injury (CIRI) for many years. However, little is known about the effects of DDTN in the treatment of CIRI from the perspective of gut microbiota and metabolites.

PURPOSE

This study aimed to investigate the regulatory roles of DDTN in endogenous metabolism and gut microbiota in CIRI rats, thus providing a basis for clinical rational drug use and discovering natural products with potential physiological activities in DDTN for the treatment of CIRI.

METHODS

The chemical composition of DDTN in vitro and in vivo was investigated using ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLCHRMS), followed by target prediction using reverse molecular docking. Secondly, a biological evaluation of DDTN ameliorating neural damage in CIRI was performed at the whole animal level. Then, an integrated omics approach based on UHPLCHRMS and 16S rRNA sequencing was proposed to reveal the anti-CIRI effect and possible mechanism of DDTN. Finally, exploring the intrinsic link between changes in metabolite profiles, changes in the intestinal flora, and targets of components to reveal DDTN for the treatment of CIRI.

RESULTS

A total of 112 chemical components of DDTN were identified in vitro and 10 absorbed constituents in vivo. The efficacy of DDTN in the treatment of CIRI was confirmed by alleviating cerebral infarction and neurological deficits. After the DDTN intervention, 21 and 26 metabolites were significantly altered in plasma and fecal, respectively. Based on the fecal microbiome, a total of 36 genera were enriched among the different groups. Finally, the results of the network integration analysis showed that the 10 potential active ingredients of DDTN could mediate the differential expression of 24 metabolites and 6 gut microbes by targeting 25 target proteins.

CONCLUSION

This study was the first to outline the landscapes of metabolites as well as gut microbiota regulated by DDTN in CIRI rats using multi-omics data, and comprehensively revealed the systematic relationships among ingredients, targets, metabolites, and gut microbiota, thus providing new perspectives on the mechanism of DDTN in the treatment of CIRI.

Elevated gut microbiota metabolite bile acids confer protective effects on clinical prognosis in ischemic stroke patients

Background

There is evidence of an association between the gut microbiota and progression of stroke. However, the relationship between gut microbial metabolites, specifically bile acids (BAs), and post-ischemic stroke disability and poor functional outcomes remains unexplored.

Methods

Patients with acute ischemic stroke (AIS) or transient ischemic attack (TIA) in the Third China National Stroke Registry were grouped according to total bile acid (TBA) quartile on admission. Association of TBA with disability and poor functional outcomes were evaluated using logistic regression models and restricted cubic splines.

Results

Data for 9,536 patients were included. After adjusting for confounders, the risks of disability and poor functional outcomes were significantly lower in the highest TBA quartile than in the lowest TBA quartile at the 3-month follow-up, with respective odds ratios (ORs) of 0.65 (95% confidence interval [CI] 0.55-0.78; p < 0.001) and 0.66 (95% CI 0.55-0.78, p < 0.001). Each standard deviation increase in the TBA level reduced the risks of disability and poor functioning outcomes by 10% (adjusted ORs 0.9 [95% CI 0.83-0.98; p = 0.01] and 0.9 [95% CI 0.83-0.97; p < 0.001], respectively). This association remained similar at the 1-year follow-up. After stratification by TOAST subtype, the risk of disability or a poor functional outcome in patients with the large-artery atherosclerosis or "other" subtype was significantly lower in the highest quartile than in the lowest quartile (p < 0.05).

Conclusion

Serum TBA is an independent risk factor for disability and poor functional outcomes after AIS or TIA, and exerts a protective effects on brain.

The NLRP3 inflammasome and gut dysbiosis as a putative link between HIV-1 infection and ischemic stroke

HIV-associated comorbidities, such as ischemic stroke, are prevalent in people with HIV (PWH). Several studies both in animal models and humans have revealed an association between activation of the inflammasome in HIV-1 infection and stroke. The gut microbiota is an important component in controlling neuroinflammation in the CNS. It has also been proposed to be involved in the pathobiology of HIV-1 infection, and has been associated with an increase in activation of the inflammasome. In this review, we provide an overview of the microbiota-gut-inflammasome-brain axis, focusing on the NLRP3 inflammasome and dysregulation of the microbiome as risk factors that may contribute to the outcome of ischemic stroke and recovery in PWH. We also focus on the potential of targeting the NLRP3 inflammasome as a novel therapeutic approach for PWH who are at risk of developing cerebrovascular diseases.