Oral bacteria can increase risk of heart disease: Research

According to the study, the bacteria that cause gum disease and foul breath may raise the risk of heart disease.

A study published today in eLife suggests that infection with a bacterium that causes gum disease and foul breath may raise the risk of heart disease. The study advises that physicians check for other potential risk factors to identify those at risk of heart disease. It could also mean that therapies for the oral bacterium Fusobacterium nucleatum may help minimise the risk of heart disease. Heart disease, which accounts for around one-third of all fatalities globally, is caused by genetic and environmental risk factors.

Coronary heart disease, the most prevalent type of heart disease, is caused by a buildup of plaque in the arteries that supply the heart with blood, and it can also lead to blockages that cause heart attacks. Previous research has linked some infections to a higher risk of plaque buildup."Although enormous progress has been made in understanding how coronary heart disease develops, our understanding of how infections, inflammation, and genetic risk factors contribute is still incomplete," says lead author Flavia Hodel, former PhD student at the School of Life Sciences of EPFL, Switzerland. "We wanted to help fill some of the gaps in our understanding of coronary heart disease by taking a more comprehensive look at the role of infections."

Hodel and colleagues analysed genetic information, health data, and blood samples from a subset of 3,459 people who participated in the CoLaus|PsyCoLaus Study -- a Swiss population-based cohort. Of the 3,459 participants, around 6 per cent experienced a heart attack or another harmful cardiovascular event during the 12-year follow-up period. The team tested participants' blood samples for antibodies against 15 different viruses, six bacteria, and one parasite.

Once the authors adjusted the results for known cardiovascular risk factors, they found that antibodies against F. nucleatum, a sign of previous or current infection by the bacterium, were linked with a slightly increased cardiovascular event risk."F. nucleatum might contribute to cardiovascular risk through increased systemic inflammation due to bacterial presence in the mouth, or through direct colonisation of the arterial walls or plaque lining the arterial walls," Hodel explains.

The authors also confirmed that individuals with high genetic risk scores for coronary heart disease are at elevated risk for cardiovascular events, as previous studies have shown. If future studies confirm the link between F. nucleatum and heart disease, the authors say it may lead to new approaches to identifying those at risk or preventing cardiovascular events."Our study adds to growing evidence that inflammation triggered by infections may contribute to the development of coronary heart disease and increase the risk of a heart attack," concludes senior author Jacques Fellay, a professor at the School of Life Sciences, EPFL, and head of the Precision Medicine Unit at Lausanne University Hospital and the University of Lausanne, Switzerland. "Our results may lead to new ways of identifying high-risk individuals or lay the groundwork for studies of preventive interventions that treat F. nucleatum infections to protect the heart."