Alzheimer's Linked to Gingivitis

A study published in Science Advances suggests an enzyme emitted by the Porphyromonas gingivalis (P. gingivalis) bacteria called gingipains is the "main cause of Alzheimer's disease," reports University of California Professor Steve Dominy in Newsweek . The investigators compared the brain tissue of persons with and without Alzheimer's, determining that 96 percent of 53 individuals with the disease had RgpB, or a form of the gingipains enzyme known as arginine-gingipain. Meanwhile, 91 percent of 54 persons had Kgp, or lysine-gingipain, and these were detected in significantly bigger concentrations than the control samples. The gene associated with P. gingivalis also was present in the brain tissue of three people with Alzheimer's and six healthy controls, via DNA testing. In addition, analysis of cerebrospinal fluid and saliva of 10 persons believed to have Alzheimer's turned up the P. gingivalis gene hmuY in seven participants, and P. gingivalis itself in all. In addition, mice dosed with gingipains exhibited higher levels of amyloid beta and greater neuronal damage. This neurodegeneration halted when the mice were treated with a drug blocking the enzymes. The researchers are hopeful that a drug that inhibits the spread of P. gingivalis in the brain could forestall the symptoms of Alzheimer's.