According to the American Heart Association, stroke is the leading cause of death, dementia and serious long-term disability in the United States.
As an aim to improve the outcomes of stroke, researchers at a university in America are pioneering research into the association between stroke-induced gut permeability, or leakiness, and cognitive impairment.
The team based at Texas A&M University School of Medicine, investigated the idea whether transplant of intestinal epithelial stem cells (IESCs) from health donors could repair the intestinal barrier after stroke onset and improve stroke outcomes.
Results from their preclinical study, indicate that IESC transplantation reduced stroke-induced cognitive impairment.
Two-thirds of stroke patients will develop cognitive impairment, while one-third of all stroke patients will go on to develop dementia, according to recent research published in the National Institute of Medicine.
Despite conventional stroke treatment research focuses on the brain, the gut responds early and rapidly to stroke with changes that may precede many of the inflammatory events associated stroke-induced disease.
These changes made in the gut, like increased permeability, will likely result in the movement of products that are synthesised in the gut into the blood stream.
Many of these products are toxic and therefore in a position to increase inflammation and exacerbate stroke-induced brain injury.
Evidence from a variety of studies demonstrate that IESCs repair the gut and reduce gut permeability.
After stroke, these repair processes may be critical to preserving cognitive function.
Senior author of the study, Farida Sohrabji, says: “It is clear that the gut-brain axis is involved in injury following stroke.
“Factoring in the effects of gut health on the brain following stroke may allow us to more effectively advance stroke therapies.”
Sohrabji and her team transplanted primary IESCs from healthy donors after stroke in a preclinical model.
IESCs from young donors repaired gut architecture and decreased gut permeability and consequently decreased blood levels of proteins and other molecules that are toxic to brain cells.
IESC transplantation also prevented depressive-like behaviours and cognitive impairment in the week following the stroke.
IESC transplantation from older donors did not improve stroke outcomes, indicating that successful transplantation depends on the age of the donor.
This study is still at it’s preclinical stage, however, it does highlight the importance of early therapeutic intervention after stroke.
Sohrabji says: “Future studies will investigate refinement of the dosing and timing of the protocol.
“A systematic study of ageing stem cells would also be important to explain why older patients experience more severe strokes.”
Sohrabji concludes by laying out her expectations of this study: “Ultimately, this research is expected to advance development of novel therapies that target and repair the intestinal epithelium to help mitigate stroke disability,”
“The premise—that gut stem cells might be therapeutically valuable outside of the gut—could be considered for a much greater variety of neurological diseases.”
