An Oral Approach to Heart Disease
THURSDAY Sept. 11, 2008 -- Irish researchers are trying to develop a new way of attacking heart disease -- through the mouth.
"We are trying to understand the mechanisms by which oral bacteria colonies can lead to cardiovascular disease," said Steve Kerrigan of the Royal College of Surgeons in Dublin, and the principal investigator in a group that will report on the effort Thursday at the Society for General Microbiology meeting in Dublin.
People with poor dental hygiene, especially those with bleeding gums, are prey to more than 700 different types of oral bacteria, Kerrigan noted. "When those bacteria get into the bloodstream, they interact with platelets, the blood cells that can clump. The bacteria can cause them to clump together to form clots that can partially block blood vessels," he said.
Kerrigan and his colleagues, including Dr. Howard F. Jenkinson of the University of Bristol, have been investigating the cell surface proteins that allow bacteria to interact with cell platelets.
"We are trying to find new drugs that prevent this interaction," Kerrigan said. "The treatment now for this condition is aggressive antibiotic treatment. With all the controversy about antibiotic-resistant bacteria that is emerging, it would be best not to use antibiotics. If we find the ways the bacteria are causing the platelets to clump, it would be a new treatment target."
Analysis of the genes of streptococci often found in the mouth has identified a number of proteins responsible for the adherence of bacteria to platelets, Kerrigan said. "We have a few targets that we are researching just now," he said. "We have some good leads at the moment, and are trying to refine what we have found."
While "there is no definitive study that shows a cause-and-effect relationship between periodontal disease and heart disease," said Sally Cram, a Washington, D.C. periodontist who is a consumer adviser to the American Dental Association, "we have a number of studies coming out that indicate a strong relationship between infection in the mouth and gums and other things in your health, such as diabetes and heart disease."
Even although the case may not be completely proven, she added, "I tell my patients that, given that periodontal disease is preventable by doing certain things that take five minutes a day, it is worth doing those things."
Cram's recommendations are standard: brush twice a day, floss once a day, see a dentist regularly or when signs of trouble appear.
"Especially if there is a family history of heart disease or diabetes, it makes common sense to help prevent gum disease," she said.
Good oral hygiene is a necessity because bacteria easily get into the bloodstream from the mouth, from routine activities such as chewing and from tooth brushing, said Peter Lockhart, chairman of the department of oral medicine at the Carolinas Medical Center, in Charlotte, N.C.
Earlier this year, Lockhart published a study of 290 dental patients showing that bacteria could be detected in 23 percent of them after tooth brushing, compared to 30 percent when a tooth was pulled after the patient took an antibiotic and 60 percent when no antibiotic was taken.
So oral hygiene is "a much more appropriate focus for prevention of endocarditis," infection of the lining of the heart or a heart valve, Lockhart said.
Posted: September 2008