Cocoa (Theobroma cacao) reduced periopathogenic bacteria and improved oral malodor

Objectives: The antibacterial effects of cocoa (Theobroma cacao) on periopathogenic bacteria including Porphyromonas gingivalis, Fusobacterium nucleatum, and Prevotella intermedia were examined and compared with those on indigenous oral streptococci. A pilot clinical trial also was conducted on volunteers to investigate whether or not cocoa reduced periopathogenic bacteria in the oral cavity, and also oral malodor. Methods: To examine antibacterial effects of cocoa, a colony forming unit (CFU) assay was performed on an agar plate. Eighteen male volunteers with P. gingivalis in their saliva were recruited for a clinical trial. The protocol for the clinical trial was designed including a preparatory phase of 7 days, cocoa-intake (8%w/v non-sugar cocoa) phase of 14 days, and post-intake phase of 7 days. The number of total bacteria, P. gingivalis, F. nucleatum, and P. intermedia in the saliva of each volunteer was evaluated by quantitative PCR. Nine out of 18 volunteers were selected for the further examination to measure their volatile sulfur compounds (VSC). Results: The growth of periopathogenic bacteria was significantly suppressed by cocoa in a dose dependent manner within 1hr of incubation. On the contrary, the cocoa showed no antibacterial effect on the growth of indigenous streptococci. A fraction of cocoa extracted with 50% methanol, showed anti-periopathogenic bacteria. This activity was completely eliminated by polyvinylpolypyrolidone. These results strongly suggest that the component in cocoa responsible for antibacterial effects against the periopathogenic bacteria is polyphenols. Conclusions: The cocoa polyphenols showed anti-periopathogenic bacteria. The results of the clinical trial showed that the ratio of each periopathogenic bacterium to total bacteria and VSC levels significantly decreased after the cocoa-intake phase. In contrast, no significant reduction in the number of total bacteria was observed. This pilot study indicates that a 2-week-cocoa-drinking could decrease periopathogenic bacteria from the oral cavity and improve oral malodor by reducing VSC.