🦠 Background: The Gut Microbiome
The gut microbiome is a highly dynamic ecosystem composed of trillions of micro organisms residing in the gastrointestinal tract. These microbes are key to essential biochemical processes including:
• Fermentation of dietary fibres into short-chain fatty acids (SCFAs)
• Regulation of immune responses
• Modulation of lipid and glucose metabolism
• Production of metabolites that influence distant organs such as the heart
Growing research highlights that disruptions in microbial composition often termed dysbiosis,are strongly associated with metabolic and inflammatory pathways implicated in cardiovascular disease (CVD).
One of the most studied microbial metabolites is trimethylamine N-oxide (TMAO). Elevated TMAO levels have been associated with atherosclerosis, endothelial dysfunction, and thrombosis risk.
❤️ Cardiovascular Health
Cardiovascular diseases remain the leading cause of mortality worldwide, an umbrella term for diseases involving the heart and blood vessels. They include conditions such as:
• Coronary heart disease
• Peripheral arterial disease
• Stroke
Traditional risk factors such as lipid profiles and chronic inflammation are now understood to be influenced by gut-derived metabolites. Recent research emphasises that the gut microbiome acts as a modifiable risk factor, capable of shaping cardiovascular outcomes through metabolic, inflammatory, and immune-mediated pathways.
🔑 Key factors to consider impacting The Gut–Heart Axis
1. Microbial diversity and richness and probiotics as a supportive adjunct
Why it matters: Greater diversity is consistently associated with metabolic flexibility, lower inflammation and reduced cardiometabolic risk.
What supports it:
• Diets rich in a variety of plant foods (fruits, vegetables, legumes, whole grains, nuts, seeds).
• Limited intake of ultra-processed foods and refined sugars.
• Regular physical activity and adequate sleep.
• Probiotics are live microorganisms, often referred to as "good" or "friendly" bacteria. Targeted probiotic supplementation can also play a supportive role in maintaining a balanced gut microbiome, particularly when combined with foundational lifestyle adjustments such as a fibre-rich diet, regular physical activity, and adequate sleep, all of which work synergistically to promote favourable health outcomes.
2. Fibre intake and Short Chain Fatty Acid (SCFA) production
Non-digestible carbohydrates (e.g., β-glucans, resistant starch, inulin) are fermented into SCFAs which:
• Improve lipid profiles (ie. LDL-C, total cholesterol).
• Enhance insulin sensitivity.
• Support tight junction integrity.
3. Dietary patterns rather than single nutrients
The most promising benefits are observed at the level of dietary patterns:
• Mediterranean-style diets (high in vegetables, fruits, legumes, nuts, whole grains, olive oil, and fish; low in red meat and processed foods) increased SCFA-producing bacteria, improved postprandial glucose metabolism, and reduced inflammatory markers.
• Polyphenol-rich diets (berries, cocoa, tea, extra-virgin olive oil, red wine in moderation) reduced TMAO in several trials, increased microbial diversity, and improved blood pressure and lipid profiles.
• Polyunsaturated fatty acid-enriched diets (walnuts, marine n-3 fatty acids, plant-based n-6/n-3 sources) increased short chain fatty acid producing bacteria and were associated with lower total cholesterol and improved blood pressure.
Conclusions
The gut microbiome is a highly dynamic community of microorganisms which plays a key role in both human health and disease. The latest scientific reviews underscore dietary choices, particularly those characteristic of the Western diet, can shift the microbiome toward a pro-inflammatory, pro-atherogenic state.
Targeted dietary interventions that also enrich microbial diversity may offer a powerful, accessible tool for improving cardiovascular markers and outcomes.
Author:
Charlotte, Co-Founder https://www.nutritional-biochemist.com
Sources:
• Akshay, A., Gasim, R., Ali, T. E., Kumar, Y. S., & Hassan, A. (2023). Unlocking the Gut-Cardiac Axis: A Paradigm Shift in Cardiovascular Health. Cureus, 15(12), e51039. https://doi.org/10.7759/cureus.51039
• Almeida, C., Gonçalves-Nobre, J.G., Alpuim Costa, D., & Barata, P. (2023). The potential links between human gut microbiota and cardiovascular health and disease - is there a gut-cardiovascular axis? Frontiers in Gastroenterology.
• Grigore, I., Ciobotaru, O. R., Hînganu, D., Gurau, G., Tutunaru, D., & Hînganu, M. V. (2025). A Systemic Perspective of the Link Between Microbiota and Cardiac Health: A Literature Review. Life (Basel, Switzerland), 15(8), 1251. https://doi.org/10.3390/life15081251
• Makkieh, Y., Shah, H.H., Imran, S.B., Pathan, S.M.K., Saju, A.C., Majooju, M., Garg, A., Naag, T., Islam, R., Fahima, C. and Ali, R. (2026). The gut-heart axis: Exploring the role of the gut microbiome in cardiovascular health – A focused systematic review. American Heart Journal Plus: Cardiology Research and Practice, 61, p.100687. doi:https://doi.org/10.1016/j.ahjo.2025.100687
• Sagmeister A, Matter CM, Stähli BE, Scharl M. The Gut–Heart Axis: Effects of Intestinal Microbiome Modulation on Cardiovascular Disease—Ready for Therapeutic Interventions? International Journal of Molecular Sciences. 2024; 25(24):13529. https://doi.org/10.3390/ijms252413529
