Gut Microbiome Could Impact Stroke Severity

New findings from Cleveland Clinic researchers show that the gut microbiome impacts stroke severity and functional impairment following it. The results, published in Cell Host & Microbe, lay the groundwork for potential new interventions to help treat or prevent stroke.

"In this study we found that dietary choline and TMAO (trimethylamine N-oxide) produced greater stroke size and severity, and poorer outcomes in animal models," said lead researcher Stanley Hazen. "Remarkably, simply transplanting gut microbes capable of making TMAO was enough to cause a profound change in stroke severity."

The researchers compared brain damage in preclinical stroke models between those with elevated or reduced TMAO levels. Over time, those with higher levels of TMAO had more extensive brain damage and a greater degree of motor and cognitive functional deficits following stroke. The researchers also found that dietary changes that alter TMAO levels, such as eating less red meat and eggs, impacted stroke severity.

"Functionality after a stroke—which occurs when blood flow to the brain is blocked —is a major concern for patients," said Hazen. According to collaborator Weifei Zhu, targeting this gut microbe enzyme may be a promising approach to prevent stroke. "When we genetically silenced the gut microbe gene that encodes CutC, stroke severity significantly diminished," she said. "Ongoing research is exploring this treatment approach, as well as the potential for dietary interventions to help reduce TMAO levels and stroke risk, since both a Western diet and a diet rich in red meat are known to elevate TMAO levels. Switching to plant-based protein sources helps to lower TMAO."