First.. what is Atherosclerosis?
Atherosclerosis is the chronic build up of plaque on artery walls. If you’d like to learn more- click here.
What Your Poop Says About Heart Health
The gut microbiota has been linked to cardiovascular diseases. In a study on the gut microbiome differences between those with atherosclerosis and healthy individuals, the microbiome from 218 individuals with atherosclerosis and 187 healthy people were compared using stool samples.
What did they find?
The gut microbiome of those with atherosclerosis differed by increased abundance of the more harmful gut bacteria’s- Enterobacteriaceae and Streptococcus. The microbiomes also differ in the potential for metabolism or transport of several molecules important for cardiovascular health.
How Does the Gut Microbiome Impact Atherosclerosis?
There have been 3 different pathways scientists think the gut microbiome may influence the development of atherosclerosis (1):
Pathway 1: (Far right) is through diet. As we discussed previously, by-products produced by gut bacteria play a role in our health. Some are helpful and some are not. A diet high in animal-based proteins and choline/carnitine, can be transformed by gut bacteria into the by-product called trimethylamine. Trimethylamine is then transformed in the liver to the compound TMAO. TMAO promotes atherosclerosis by creating higher rates of clotting events through platelet activation.
Pathway 2: (Far left) Bacterial infection can also trigger an inflammatory response by the immune system. The inflammatory response increases levels of cytokines. Cytokines are how our bodies create more inflammation. In the case of infection, this is helpful in healing. However, long term inflammation increases the risk of a cardiac event as the cytokines can enter the blood circulation and affect the progression of atherosclerosis.
Pathway 3: (Center picture) The third potential pathway is that bacteria balance can influence how fat and cholesterol are broken down which can increase the amount of fat and cholesterol present. In fact, some bacterial species can transform bile acids into secondary bile acids that enter the circulation. These secondary bile acids can then activate other receptors that influence and disrupt lipid and glucose metabolism leading to further issues.
The Bottom Line
TMAO links to higher clotting events, and promotes atherosclerosis or narrowing of the arteries. A good way to prevent this process is to consume a diet that’s mostly plant based. Ensuring a healthy diet can help you to maintain a balanced gut microbiome which reduces the risk of infection, inflammation and ensures fat and cholesterol are completely broken down.
Image inspired by: Jonsson and Bäckhed 20171 & Microba
References
1. Jonsson AL and Bäckhed F. (2017). Role of gut microbiota in atherosclerosis. Nature Reviews Cardiology.14:79-87. https://doi.org/10.1038/nrcardio.2016.183
2. Gut Microbiome in Atherosclerosis Link: https://www.nature.com/articles/s41467-017-00900-1.pdf