Chewing Gum Containing Citric Acid Reduces the Burden of Periodontal Pathogens

Objective: In a preliminary study, we noted that citric acid has the potency to induce human beta defensins (hBD-2) in salivary secretions. As hBDs are thought to ameliorate periodontal disease by suppressing key periodontal pathogens we developed a citric acid-containing chewing gum (CA-gum) to test this hypothesis. Here we report, the effect of CA-gum on three major periodontal pathogens Prevotella intermedia (Pi), Tannerella forsythia (Tf), Treponema denti- cola (Td) and Fusobacterium species (Fb). Methods: A randomized, double-blind, placebo-controlled trial with 61 individuals, was conducted over 14 days. Each subject was allowed to chew CA-gum (31 subjects) or placebo gum (30 subjects) at irregular intervals, but was instructed to eat at least three pieces of gum a day. None had active caries, symptoms of gingivitis or periodontal disease, smoking history, or concurrent medication. To determine the levels of oral carriage of the putative pathogens, saliva was collected from each subject by paraffin chewing in a standard manner and, the number of total cultivative microorganisms (CFUs) determined. Five key periodontal pathogens, Pg, Pi, Tf, Td and Fb present in saliva were determined quantitatively using real-time polymerase chain reaction (PCR) (BML Inc., Saitama, JAPAN). Results: Compared with the placebo chewing gum group the CA-gum group had significantly lower levels of Prevotella intermedia, Tannerella forsythia, and Fusobacterium spp. in their saliva. (Wilcoxon t-test; p 0.05).