A method and system of reducing the likelihood of a Porphyromonas gingivalis infection in a human being includes the use of a bioadhesive strip that binds to a person's mucosal membrane for at least 1 hour while inside a person's mouth, where the strip has a therapeutically effective amount of an anti-biofilm agent, compounds that facilitate the growth of desired bacteria beneficial to a person's health, and an antibiotic effective amount to kill Porphyromonas gingivalis bacteria. The method and system reduces the virulence factor gingipain. In other embodiments, the likelihood that a subject will suffer from Alzheimer's Disease is reduced by administering, via local gingival application to a subject that has been diagnosed with periodontitis, an effective amount of an antibiotic effective to kill Porphyromonas gingivalis bacteria residing on the subgingival tooth area of the subject.
