London, Apr 18 (IANS): A drop in the level of protein called Del-1 is why gum diseases become more common with old age, says a new research.

Periodontitis is a gum disease which causes bleeding and bone loss and leads to loss of teeth. It is triggered by an overactive immune response to mouth bugs. As people age, they are more likely to suffer from such diseases.

Researchers from Queen Mary University of London suggest that understanding more about Del-1 and its effects on the body's immune system can improve treatment or prevention of serious gum diseases, the journal Nature Immunology reports.

Mike Curtis, professor of microbiology at Queen Mary who led the study, said: "Periodontitis is an extremely common problem and we know that the disease tends to be more common as we get older."

"This research sheds light on why ageing makes us more susceptible, and understanding this mechanism is the first step to an effective treatment," he said, according to a Queen Mary press statement.

The research investigated gum disease in young and old mice and found that an increase in gum disease in the older animals was accompanied by a drop in the level of Del-1. This protein is known to restrain the immune system by stopping white blood cells from sticking to and attacking mouth tissue.

Mice that had no Del-1 developed severe gum disease and elevated bone loss and researchers found unusually high levels of white blood cells in the gum tissue. When they treated the gums of the mice with Del-1, the number of white blood cells dropped, and gum disease and bone loss were reduced.