According to new atlas, researchers have found several strains of intestinal bacteria that are associated with the severity of a common stroke** These findings build on a growing number of studies that suggest that future therapies for the intestinal microbiome can reduce a person's risk of stroke and help them recover.
The new study, which has not yet been peer-reviewed and published, was presented at this year's European Stroke Organization Conference. Led by Miquel lled ó s of the Sant Pau Institute in Spain, the study analyzed some fecal samples taken from patients with ischemic stroke.
"In this study, we took fecal samples from 89 people who suffered from ischemic stroke - the first samples after the event," explained lled ó s. "Compared with the control group, we were able to identify multiple groups of bacteria associated with a high risk of ischemic stroke."
The study identified several specific types of bacteria that may be associated with the severity of acute stroke, including negativibacillus and lentisphaeria. After three months of follow-up, the researchers also found that some bacteria were related to functional recovery. In particular, the researchers noted that a bacterium called acidaminococcus was associated with poor recovery three months after an acute stroke.
"This discovery opens an exciting prospect that in the future, we may be able to prevent stroke or improve the recovery of the nervous system by examining the intestinal microbiota. In other diseases, clinical trials are under way, and researchers replace the intestinal microbiota by changing the diet or transplanting the feces of healthy people, which should be further studied in the field of stroke," said LED ó s
Another new study presented at the meeting supports the findings of lled ó s. A Yale team revealed that they found about 20 intestinal bacteria that may be associated with an increased risk of ischemic stroke.
Cyprien Rivier, a researcher at Yale University, said his team's genetic analysis technology provided insight into the causal relationship between these types of bacteria and stroke. However, the exact mechanism by which gut bacteria may affect stroke risk remains unclear.
"Bacteria can release toxins into the blood, and they can also produce certain proteins that interfere with physiological processes," Rivier explained to the guardian. "And what we call the microbiota gut brain axis - the two-way path between the brain and the microbiota, that is, the brain affects the gut through nerves, and the microbiota in turn affects organs, including the brain, mainly by changing blood pressure."
Past studies have provided clues on how the intestinal microbiome affects stroke risk. A key study published last year by Cleveland Medical Center described the link between a metabolite produced by intestinal bacteria called TMAO (trimethylamine N-oxide) and the severity of stroke.
TMAO is produced in the gut when certain types of bacteria digest animal products, such as red meat. In preclinical tests, the Cleveland medical center study found that stroke severity increased when mice were transplanted with a large number of TMAO producing intestinal bacteria.
Interestingly, the relationship between the gut and the brain may not be a one-way process. The study proposed in 2019 found that stroke can directly cause changes in the intestinal microbiome of animals. Therefore, although the gut may be affecting the brain, brain damage will then have a significant impact on the gut.