The Pharmacogenomics and Neurovascular Genetics Group of the Sant Pau Research Institute (IR Sant Pau) has conducted a pioneering study that reveals significant differences in gut microbiota between men and women who have suffered an ischemic stroke. This research highlights the importance of biological sex in studies related to cerebrovascular disorders and gut microbiota.
The study, published in the European Journal of Neurology, was carried out within the framework of the Maestro project, granted to Dr. Israel Fernández-Cadenas, head of this research group, by the Carlos III Health Institute.
Ischemic stroke, a cerebrovascular disease affecting blood flow to the brain, maintains a well-established connection with gut microbiota through the bidirectional gut-brain axis. Until now, no data were available relating the intestinal microbiota to the sex of ischemic stroke patients. According to Dr. Miquel Lledós, from the Pharmacogenomics and Neurovascular Genetics Group of IR Sant Pau and principal investigator of the study, “the vast majority of microbiota research related to stroke does not delve into specific microbial species. We wanted to work with more specific techniques that allow us to study these species, which are ultimately the most important.“
The study involved a cohort of 89 patients who had suffered an ischemic stroke and included 12 healthy individuals as a control group. Researchers analyzed taxonomic differences in gut microbiota between men and women with ischemic stroke using complete metagenomic sequencing.
Analysis results revealed that men who have suffered an ischemic stroke exhibit greater species diversity compared to affected women. Additionally, sex differences were found in ischemic stroke patients regarding the Fusobacteriaceaefamily. It was also observed that these bacteria were not a consequence of the stroke but were already present before experiencing it, thus constituting a risk factor for the manifestation of this disease.
Dr. Fernández-Cadenas comments that the bacteria found in the group of women who had suffered an ischemic stroke “were different from the controls, and we don’t see this in men. In the group of men, there were no differences between stroke patients and controls; therefore, these bacteria were specific to stroke risk in women. Additionally, we validated this with bioinformatics studies, where we saw that these bacteria were not a consequence of having had a stroke but were present before it, and therefore, were a risk factor.”
This study is the first to indicate that there are differences in gut microbiota between men and women who have suffered an ischemic stroke, identifying high levels of Fusobacteriaceae in women as a specific risk factor for the disease. This finding underscores the importance of including biological sex in the design, analysis, and interpretation of studies on stroke and gut microbiota.
