A new study has identified strains of gut microbiota that are associated with more severe strokes and worse post-stroke recovery, revealing that the gut microbiome could be an important factor in stroke risk and outcomes.
The study, presented at the European Stroke Organisation Conference (ESOC 2022; 4–6 May, Lyon, France), pinpointed specific groups of bacteria associated with poorer neurological recovery from ischaemic stroke—both in the acute phase (24 hours) and after three months. The research identified multiple types of bacteria that were associated with ischaemic stroke risk, including Fusobacterium and Lactobacillus.
Negativibacillus and Lentisphaeria were associated with a more severe stroke in the acute phase, at six and 24 hours respectively, and Acidaminococcus related to poor functional outcomes at three months.
Miquel Lledós (Sant Pau Research Institute, Barcelona, Spain), lead author of this research, commented: “The influence of the gut microbiome—the trillions of bacteria and other microorganisms that live in the gut—is a modifiable risk factor associated with the risk of stroke and with post-stroke neurological outcomes. However, most research has previously been done in animal models.
“In this study, we took faecal samples, the first samples taken after the event, from 89 humans who had suffered an ischaemic stroke. Comparing with a control group, we were able to identify multiple groups of bacteria that were associated with a higher risk of ischaemic stroke.
“The discovery opens the exciting prospect that, in the future, we may be able to prevent strokes or improve neurological recovery by examining the gut microbiota. In other pathologies, clinical trials are being carried out where researchers replace the intestinal flora through dietary changes or faecal transplantation from healthy individuals, and this should be studied further in the stroke field.”
The association between certain strains of gut bacteria and risk of ischaemic stroke was reinforced in another study presented at ESOC 2022 by a team from Yale University (New Haven, USA). The researchers analysed statistics from the Flemish Gut Flora Project and the MEGASTROKE consortium using a technique called Mendelian Randomisation, which measures variation in genes to examine the causal effect of an outcome or exposure. The study identified 20 microbial traits significantly associated with the risk of developing at least one subtype of ischaemic stroke.