A new study has found that changes in gut bacteria may play a significant role in the recurrence of ischaemic stroke. Researchers identified distinct differences in the gut microbiota of patients who had experienced a recurrent stroke compared to those who had suffered their first stroke. The findings, published in the journal Neuroscience, raise the possibility of using gut microbial markers to predict and potentially prevent future strokes.
Scientists from Fujian Medical University conducted the study, analysing stool samples from stroke patients to assess the composition of their gut bacteria. They discovered that patients with recurrent strokes exhibited notable alterations in their gut microbiome. Certain bacteria linked to anti-inflammatory properties, including short-chain fatty acid-producing microbes, were significantly depleted in these patients. At the same time, metabolic changes affecting lipid and carbohydrate pathways were also observed, suggesting a link between gut-derived metabolites and stroke progression.
The gut microbiome, a complex community of trillions of microorganisms, has been increasingly recognised as a factor in neurological health. Previous research has established connections between gut bacteria and brain disorders, including Parkinson’s disease and Alzheimer’s disease. However, the role of gut microbes in stroke, particularly its recurrence, has remained largely unexplored. This study provides new insights into how microbial imbalances might influence the risk of subsequent strokes.
One of the key findings was the depletion of Lachnospiraceae and Prevotella bacteria in patients who had suffered a second stroke. These bacteria are known for their role in maintaining gut health and regulating inflammation. Their reduction suggests that gut microbial disturbances could contribute to increased neuroinflammation, a known risk factor for stroke recurrence. Additionally, the study found disruptions in metabolic pathways related to arachidonic acid and linoleic acid, compounds involved in inflammatory responses. Such imbalances could exacerbate vascular conditions, making patients more susceptible to another stroke.
The study also explored the role of trimethylamine N-oxide (TMAO), a metabolite produced by gut bacteria that has been associated with cardiovascular disease. Elevated levels of TMAO have been linked to increased platelet reactivity and thrombosis, both of which contribute to stroke risk. While previous research has identified TMAO as a potential biomarker for stroke, the new findings highlight its relevance in recurrent cases, indicating that gut microbial alterations may persist beyond the initial stroke event.
The implications of these findings are significant for stroke prevention and treatment. If gut microbiome alterations contribute to stroke recurrence, interventions such as probiotics, dietary modifications, or targeted therapies could help restore microbial balance and reduce the likelihood of further strokes. Further research is needed to determine whether modifying the gut microbiome could become a viable strategy for stroke prevention.
While the study provides strong evidence for the role of gut bacteria in stroke recurrence, researchers caution that more work is needed to establish causation. Clinical trials investigating microbiome-targeted therapies could help determine whether interventions can effectively lower stroke risk. Future studies may also explore how lifestyle factors such as diet and medication influence gut microbial changes in stroke patients.
