Decrease of halitosis by intake of manuka honey

Objectives: Increasing number of people is worrying about their oral halitosis. The major source of halitosis is volatile sulfur compounds (VSCs), which are generated through the decomposition of protein contained in food residue in mouth by oral bacteria such as Porphyromonas gingivalis or Fusobacterium nucleatum. Manuka honey, derived from the Manuka tree (Leptospermum scoparium) in New Zealand, is well-known for a pronounced antibacterial activity which can not be found by any other honey. Manuka honey contains a typical antibacterial substance “methylglyoxal (MGO)”, and shows the strong antibacterial activity against oral bacteria, by which it can be a promising functional food for the oral care. Here, we report on the decrease of halitosis by intake of manuka honey.

Methods: Ten healthy subjects (average age : 36 years old, 5 men and 5 women) were selected, and their halitosis was measured before and after intake of manuka honey or acacia honey. The concentration of VSCs was measured by an oral chroma (Halimeter RH-17K, Taiyo), and the concentration of anaerobic bacteria in mouth was evaluated by urease activity (Atein mBA-400, Taiyo). The amount of MGO in honey was measured using RP-HPLC with UV detection as the corresponding quinoxaline after pre-column derivatization with o-phenylendiamine (Mavric et al. 2008).

Results: The concentrations of VSCs and anaerobic bacteria in mouth decreased after intake of both honey, but the decreasing effect of manuka honey was markedly stronger than that of acacia honey. Manuka honey showed 127 times higher amount of MGO than acacia honey by RP-HPLC analysis.

Conclusions: Since there is the strong relationship between MGO level in honey and the antibacterial activity, the results indicate that the decreasing effect of halitosis by manuka honey would originate from the strong antibacterial activity of MGO.