Bacteria in Mouth and Gut Can Cause Clogged Arteries and Heart Disease
등록일 2017년 11월 06일 월요일
수정일 2017년 11월 06일 월요일

Enterococcus faecalis bacteria known as Streptococcus faecalis / Photo by: via Shutterstock

Researchers from the University of Connecticut discovered that bacteria in our mouth and gut may clog blood vessels.Their findings may explain on why gum disease is linked to atherosclerosis, a condition wherein the blood vessel becomes clogged with plaque.Another important detail they found is the relation between the immune system and the inflammation of arteries.

The hardening and narrowing of the arteries is called atherosclerosis and it can cause different health problems.Stroke, heart attack, and cardiovascular diseases are just some of the complications of atherosclerosis.Healthy blood vessels including arteries have a thin layer of endothelium, cells that keep the inside part of arteries smooth and tones.Atherosclerosis begins with the damage of endothelium caused by smoking, high cholesterol levels, and high blood pressure.It then leads to the formation of plaque composed of low-density lipoprotein or bad cholesterol sipping inside the damaged endothelium, and white blood cells digesting LDL.Over the years, the accumulated amount LDL and white blood cells will create a bump on the arterial wall, which can block blood flow.The blocked blood flow of arteries may cause pain in certain parts of the body like your arm, chest or leg.But if the plaque breaks off, this can cause the blood to clot inside the artery and lead to a brain stroke, a heart attack or lung embolism.

It was previously assumed that eating too much fat is the primary cause of plaque to build up inside blood vessels.However, pieces of evidence tell that this is not the entire story about plaque and atherosclerosis.This is because some people do not develop cardiovascular diseases no matter how much fat they consume.

Involvement of Bacteroidetes

Bacteroidetes are widely distributed microorganisms in the environment.They can be found in soil, sediments, and seawater.They can also be found in the guts and skins of animals, including humans.The bacteroides found in feces of warm-blooded animals and humans, and the Porphyromonas found in the human oral cavity are the most studied bacteria from class Bacteroidetes.

The researchers found that the signature of fat molecules or lipids in atheromas in the arterial wall belonged to the bacteriodetes.Atheromas are growths in the inner part of the arterial walls, consisting of debris, lipids, and white blood cells.The bacteria produce fats that contain branched chains and a weird number of carbon atoms, unlike fats found in animals.

"We used these weight differences and modern mass spectrometers to selectively measure the quantity of the bacterial lipids in human samples to link the lipids to atherosclerosis," said Xudong Yao, an associate professor of chemistry at UCONN and a researcher involved in the study.

Bacteriodetes colonize the oral cavity and the gut of humans, and they are usually harmless.But the lipids they produce can reach the bloodstream causing it to build up in the arterial wall.

Involvement of the Immune System

The researchers discovered that the immune system has something to do with the inflammation of the arteries.The blood white cells, specifically macrophages, attack the fatty deposits produced by the bacteria since they are foreign.As the macrophages attack the foreign fats, an enzyme breaks down the bacterial lipids into molecules that assist inflammation.The immune system works normally in response to anything it detects as foreign.Inflammation usually follows whenever the immune system is clearing something foreign or countering an invasion, an example of which is the site of a wound.

The researchers of UCONN are now working for more information on where the bacteria accumulate lipids, and if these lipids also build up in atheromas, not in the arterial wall.If the researchers discover that the bacterial fats build up in atheromas, it will give more evidence in linking atheroma growth and heart disease with the fatty acids from bacteroidetes.

Treatment for Atherosclerosis

A blockage that developed usually stays in the artery for life and the accumulation can be slowed down with lifestyle changes.These lifestyle changes, such as regular exercises, quitting smoking, and eating a healthy diet, reduce the risk of atherosclerosis.Medications prescribed by doctors also help control your elevated cholesterol levels and high blood pressure.Managing these factors help reduce the chance of heart attack or brain stroke.In severe cases of atherosclerosis, doctors may perform angiography and stenting, and bypass surgery.

1.Angiography and stenting - It involves a thin tube to be inserted into an artery of the arm or leg for doctors to reach the diseased artery.Angioplasty or catheters with balloon tips and stent are used to open up the blocked artery.

2.Bypass surgery - It involves the harvesting of a healthy blood vessel and using it to go around the blocked segment of the artery.

World Health Organization Facts

- About 17.7 million people die every year because of cardiovascular diseases.

- About 75 percent of deaths associated with CVD came from low-income and middle-income nations.

- About 80 percent of deaths associated with CVD were heart attacks and brain strokes.

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