Gut microbes may reduce heart disease risk, shows new research

A low diversity of gut bacteria may help explain heart attacks in young people, women and certain ethnic groups

You can influence your gut microbes by eating good bacteria, found in probiotic foods (Getty)

Research has shown that having the right gut microbes can reduce the risk of heart disease – if you’re a mouse. Now, our latest study, published in the European Heart Journal, shows that this might be true for humans, too.

Most people know that the risk factors for heart disease are high blood pressure, high cholesterol and smoking.

But these factors are not very good at predicting heart disease in younger people, in women and in some ethnic groups. A poor gut microbiome could be the missing risk factor we’ve been looking for.

One of the ways that the risk of heart attack or stroke is assessed is by measuring the hardening of the arteries. This measure, called arterial stiffness, is not strongly associated with high cholesterol or smoking, but it is closely related to inflammation.

Inflammation is our body’s normal response to injury, but when it is too high, in a way that is not a response to injury, it can cause many diseases, such as arthritis and eczema.

Studies have shown that the more inflammation a person has, the higher their risk of heart disease and of having artherosclerotic arteries.

Recently, several large clinical studies have shown that inflammation is a key factor in the development of heart disease and stiffening of the arteries.

In one study, giving people a drug that reduces inflammation brought down the number of heart attacks in people who had already had one heart attack. It also brought down their risk of cancer.

But how can we reduce inflammation without fancy drugs? Avoiding obesity and smoking are a good start, but the good bacteria that live in our gut can also help.

You can give your gut bacteria a helping hand by eating a high-fibre diet (Getty)

The microbes that live in our gut seem to be important in preventing a number of diseases caused by inflammation such as psoriatic arthritis, diabetes and gut conditions like inflammatory bowel disease.

In all of these diseases, it has been found that there is a lack of diversity of healthy gut bacteria, which means there are fewer kinds of microbes.

In our study, we found that women with more hardening of the arteries have lower microbial diversity in their gut, and that the women with healthier arteries have more diversity. Not only that, certain beneficial substances produced by microbes were also seen at higher levels in the blood of people with healthier arteries.

This substance, indolepropionic acid, has previously been shown to predict a lower risk of developing diabetes. Bacteria in the gut produce more indolepropionic acid when a person eats a diet high in fibre.

Overall, we found that almost 10 per cent of the amount of arterial hardening was explained by the gut microbes and substances produced by the microbes. In comparison, cholesterol levels, smoking, diabetes and middle obesity explained less than 2 per cent of this measure of risk of heart disease.

This is very exciting because, unlike genetic risks, which we can’t do much about, the microbes in the gut and the substances they produce can be changed.

One way to influence the gut microbes is to eat good bacteria. This can be done by eating probiotic foods or supplements, or by having a faecal transplant, a procedure in which part of a stool is taken from one person and given to another, introducing beneficial microbes to the receiving patient’s digestive system.

Ana Valdes is an associate professor and researcher at the University of Nottingham. This article was originally published in TheConversation.com