The Gut-Brain Axis: How Gastrointestinal Health Influences Stroke Risk?
Introduction –
Gut-brain axis or GBA has been a recent topic of scientific research and finds a bi-directional correlation between gut issues and neurological health conditions. The biological mechanism is quite complex, wherein the microbiome of the digestive tract interacts with the nervous system and influences the body’s immune response, inflammation and even mood. Surprising relation explored by scientists in recent years is the implication of the gut microbiota on an individual’s stroke risk.
Relation between dysbiosis of gut microbiome and risk of stroke –
Stroke occurs when there is blockage or bleeding in the blood vessels of the brain. The microbiome of the gut has the ability to alter the vascular function and thereby, gut dysbiosis can lead to stroke undoubtedly.
- Chronic Inflammation – When an imbalance occurs in the gut microbiota, this may lead to chronic inflammation in the body, a leading risk factor for stroke. This happens due to the production of pro-inflammatory cytokines which affect the blood flow in the brain vessels, causing atherosclerotic plaques which can rupture and cause stroke.
- High blood pressure – Research has proven a direct association between hypertension and stroke risk and the interesting part is that gut microbiome can alter blood pressure. When the microbiome gets disturbed, blood pressure rises and this may lead to stroke.
- Maintaining the integrity of blood-brain barrier (BBB) – The brain gets protection from the harmful substances and toxins present in the blood via a shield known as blood-brain barrier, the integrity of which is aided by the short-chain fatty acids (SCFAs) released as metabolites by a good gut microbiota. If the gut microbiome gets disturbed, it can make the brain susceptible to stroke by altering BBB.
- Atherosclerosis by gut microbiota metabolites – When foods such as red meat, eggs etc. are consumed, choline present in them gets metabolized by the gut bacteria into trimethylamine-N-oxide (TMAO) which can lead to atherosclerosis and increase the risk of stroke.
- Immune system modulation – The gut has a lot of immune cells and if the microbiome of the gut gets disturbed, it affects the body’s immunity and can lead to stroke due to vascular changes.
- Production of reactive oxygen species (ROS) – When there is dysbiosis, there is oxidation of the body cells and production of reactive oxygen species (ROS). ROS is responsible for destruction of the inner lining of the blood vessels (endothelial layer), which is crucial for vascular health. This in turn makes the vessels weak and predisposes them to the risk of stroke due to plaque buildup.
Bottom line – The gut microbiome has a link with the central nervous system and influences the risk of stroke. That is why it is essential to maintain a healthy gut to keep the nervous system healthy, free from vascular conditions
