The gut wall’s integrity, especially its tight junctions, is crucial for a healthy barrier, preventing “leaky gut.” These junctions act as selective gates, allowing nutrients in while blocking harmful substances like undigested food particles, toxins, and bacterial components (e.g., LPS) from entering the bloodstream.

When factors like stress compromise these tight junctions, the gut becomes “leaky”. This allows harmful substances to “leak” into the bloodstream, triggering a systemic inflammatory response.

This chronic inflammation damages the inner lining of blood vessels (endothelium), making them susceptible to plaque buildup which is atherosclerosis. Immune cells and cholesterol accumulate at these damaged sites, forming plaques. Research even suggests bacterial components from a leaky gut can directly contribute to plaque formation.

As plaques grow, they narrow the arteries, restricting blood flow. This arterial narrowing and inflammation are root causes of serious health issues like strokes, and peripheral artery disease, highlighting the link between gut health and cardiovascular well-being.
The vagus nerve facilitates crucial bidirectional communication between the brain and gut. From gut to brain, it relays sensory information about gut contents and microbiome activity, influencing mood and stress. From brain to gut, it regulates digestion, motility, and immune responses.

Under stress, vagal activity can be inhibited, sending signals to the gut that compromise the integrity of its lining. Specifically, the tight junctions—proteins sealing gut cells—can partially break down.

This breakdown leads to increased intestinal permeability, allowing harmful substances like undigested food particles, toxins, and bacterial components (e.g., LPS) to leak from the gut into the bloodstream. The immune system identifies these as foreign, triggering chronic systemic inflammation.

This persistent inflammation damages the inner lining of the arteries (endothelium). This damage promotes the accumulation of cholesterol and immune cells, forming plaque buildup (atherosclerosis). As plaques grow, they narrow the arteries, restricting blood flow and leading to serious health issues. Thus, maintaining gut wall integrity is vital for overall cardiovascular health.