Gut Microbe Strains Linked to More Severe Strokes

The human microbiome is composed of bacteria, archaea, viruses and eukaryotic microbes that reside in and on individual bodies. These microbes have tremendous potential to impact that physiology, both in health and in disease.

Globally, about 13 million people experience a stroke each year and about 5.5 million people die from strokes. A stroke happens when blood is not able to reach the brain. If blood flow to the brain becomes blocked, oxygen and vital nutrients cannot get to the brain, which can cause brain cells to die.

Image: Gram staining of Negativibacillus massiliensis bacteria isolated from a human left colon sample (Photo courtesy of Aix Marseille University)

Medical Scientists at the Sant Pau Research Institute (Barcelona, Spain) and their colleagues have linked specific bacteria in the gut microbiome to both stroke severity and recovery. The team analyzed studied samples from 89 ischemic stroke patients and 12 controls. They performed shotgun metagenomics sequencing to analyze the taxonomic profiles.

The scientists identified multiple types of bacteria associated with an increased risk for ischemic stroke, including the bacteria Fusobacterium and Lactobacillus. They also found the bacteria Negativibacillus and Lentisphaeria were associated with a more severe stroke in the acute phase and the bacteria Acidaminococcus led to poor post-stroke recovery after three months.

Miquel Lledós, PhD, the lead author of the study, said, “Acidaminococcus is an opportunistic pathogen, and this genus has already been related to a higher risk of stroke.” Acidaminococcus is a member of the family Veillonellaceae, known for producing succinate, a compound linked to increased risk factors for cardiovascular disease.”

Dr. Lledós added, “In other pathologies, clinical trials are being carried out in which scientists replace the intestinal flora through dietary changes or fecal transplantation from healthy individuals that is much more consistent in the long term. One way to do that is by using lyophilized compounds of microorganisms in capsules that are easy to ingest and that modify the intestinal flora.”

The authors concluded that multiple new taxonomic profiles associated with stroke, revealing that gut microbiome could be an important factor associated with stroke risk and stroke acute and long-term outcome. The study was presented at the 2022 European Stroke Organisation Conference held May 4-6, 2022 in Lyon, France.

Related Links:
Sant Pau Research Institute