What TMAO levels are associated with poor outcomes after my stroke?
Trimethylamine N-oxide (TMAO) is a gut-derived metabolite that has been linked to inflammation and blood clotting. After a stroke, higher TMAO levels in the blood may signal a higher chance of poor recovery. Research shows that patients with the highest TMAO levels have a significantly greater risk of disability or death within 3 to 12 months.
What the research says
A 2019 study of 225 acute ischemic stroke patients found that those with TMAO levels in the highest quartile (roughly above 4.8 µM) had a 3.6 times higher risk of poor functional outcome at 3 months compared to the lowest quartile, after adjusting for other risk factors 9. The median TMAO level in that study was 3.8 µM 9. Another 2020 study of 204 stroke patients reported that each unit increase in log-transformed TMAO level was linked to a 2.9 times higher risk of unfavorable functional outcome (modified Rankin Scale score ≥3) at 90 days, and a 2.6 times higher risk of major ischemic events (like another stroke or heart attack) at 12 months 10. A more recent study (2025) of 213 patients who underwent endovascular therapy found that higher TMAO levels from the culprit vessel were independently associated with poor 3-month outcomes, and combining TMAO with the neutrophil-to-platelet ratio improved prediction 5. Notably, TMAO levels tend to drop after the first day of stroke treatment, so early measurement may be most informative 10.
What to ask your doctor
- Should I have my TMAO level checked to help assess my risk of poor recovery?
- If my TMAO is high, are there any dietary changes (like reducing red meat or eggs) that might lower it?
- How do my TMAO levels compare with other risk factors like my NIHSS score or ASPECTS score?
- Are there any treatments or lifestyle steps that can reduce TMAO and improve my stroke recovery?
This question is drawn from common patient questions about this topic and answered using cited medical research. We do not provide individualized advice.