Low levels of diversity in ‘good bacteria’ in our digestive systems is linked to hardening of the arteries, a feature of cardiovascular disease, finds new research from King’s College London and the University of Nottingham. The work suggests that targeting microorganisms in the gut using diet, medication and probiotics may increase the range of bacteria found and reduce the risk of cardiovascular disease.

The gut microbiome – a collection of micro-organisms in the gut that include bacteria, fungi and viruses - is under increasing scrutiny in medical research as it is known to affect many different aspects of our health, including our metabolism and auto-immune system. A lack of diversity or range of healthy bacteria in the gut has previously been linked to various health problems, including diabetes, obesity and inflammatory stomach and bowel diseases.

Now for the first time, researchers have found a link between gut bacteria and arterial stiffening.

Dr Cristina Menni from the Department of Twin Research and Genetic Epidemiology, and colleagues examined medical data from a group of 617 middle-aged female twins from the TwinsUK registry. Measurements of arterial stiffening were analysed alongside data on the composition of the gut microbiomes of the women and results revealed a significant correlation between the diversity of the microbes in the gut and the health of the arteries. After adjusting for metabolic variations and blood pressure, the team found that arterial stiffness was higher in women with lower diversity of healthy bacteria in the gut. The research also identified specific microbes which were linked to a lower risk of arterial stiffening. 

The researchers conclude that cardiovascular risk that is not due to the usual risk factors, such as smoking and obesity, could in future be explained by analysing the health of the gut microbiome. This could be particularly useful in explaining cardiovascular risk in younger people and in women.

Dr Cristina Menni, from the Department of Twin Research and Genetic Epidemiology at King’s College London, said: “There is considerable interest in finding ways to increase the diversity of gut microbes for other conditions such as obesity and diabetes. Our findings now suggest that finding dietary interventions to improve the healthy bacteria in the gut could also be used to reduce the risk of heart disease.” 

Dr Ana Valdes, from the University of Nottingham’s School of Medicine and NIHR Nottingham Biomedical Research Centre, said: “We know that a substantial proportion of serious cardiovascular events like heart attacks are not explained by traditional risk factors such as obesity and smoking, particularly in younger people and in women and that arterial stiffness is related to risk in those groups. So our results reveal the first observation in humans linking the gut microbes and their products to lower arterial stiffness. It is possible that the gut bacteria can be used to detect risk of heart disease and may be altered by diet or drugs to reduce the risk.”

The research was funded by the British Heart Foundation and Medical Research Council and is published in the European Heart Journal