The Study
Polyphenol-mediated microbiome modulation in STEMI patients: a pilot study
This study gave some heart attack patients a grape extract and others a fake one, then checked their gut bacteria. It found that the grape extract group had different bacteria and didn't have rising TMAO levels. But it doesn't prove the grape extract caused these changes—it just shows they happened together.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
After a heart attack, some gut bacteria make a chemical called TMAO that can harm your heart. This study gave people a grape juice concentrate to see if it could change their gut bacteria to be healthier.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 581 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1This suggests the grape juice may help protect the heart by changing gut bacteria to make less harmful TMAO — but it’s not proven to prevent future heart problems yet.
- 2People who drank the grape concentrate had stable TMAO levels (no increase), while those who drank placebo had TMAO levels double.
- 3Their good gut bacteria (Roseburia, Agathobaculum, Alistipes finegoldii, Sellimonas) went up, and bad ones (Alistipes timonensis, Parabacteroides goldsteinii) went down.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Frontiers in Medicine
Year
2025
Authors
A. Issilbayeva, S. Sergazy, A. Zhashkeyev, A. Gulyayev, S. Kozhakhmetov, Z. Shulgau, M. Nurgaziyev, A. Nurgaziyeva, Sanzhar Zhetkenev, N. Mukhanbetzhanov, Zharkyn Jarmukhanov, Zhanel Mukhanbetzhanova, E. Vinogradova, Z. Zhumadilov, A. Kushugulova, M. Aljofan
Related Content
Claims (6)
Consuming colorful plant foods provides polyphenols that directly increase the activity and diversity of gut microbes.
In patients with STEMI, polyphenol supplementation is linked to higher levels of Alistipes finegoldii and lower levels of Alistipes timonensis; higher Alistipes finegoldii levels are associated with lower plasma TMAO levels, while higher Alistipes timonensis levels are associated with higher plasma TMAO levels.
In people who have had a heart attack called STEMI, taking polyphenol supplements is linked to higher levels of two gut bacteria, Sellimonas and Agathobaculum, that produce butyrate and are associated with reduced activity of bacteria that make TMAO.
In patients who have had a specific type of heart attack, taking 15 mL of grape polyphenol concentrate daily for three months is linked to no change in plasma TMAO levels, while those taking a placebo show a measurable increase in plasma TMAO levels.
In patients who have had a heart attack called STEMI, taking polyphenol supplements for three months is linked to a decrease in the ratio of Firmicutes to Bacteroidetes gut bacteria and an increase in specific butyrate-producing bacteria.
In patients who have had a heart attack called STEMI, taking polyphenol supplements is linked to lower levels of two gut bacteria, Parabacteroides goldsteinii and Lactobacillus salivarius, which have been connected to the production of trimethylamine N-oxide and lipid metabolism.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.