Public Release: 

Bacteria feed on smelly breath (and feet)

Press release based on a recently published article in Environmental Microbiology, August 2005

Blackwell Publishing Ltd.

Researchers have isolated bacteria which can grow on and 'mop up' smelly compounds in the mouth that are linked to bad breath. These smelly, highly reactive 'one-carbon' compounds are naturally produced from the breakdown of sulphur-containing amino acids in the mouth.

Dr Ann Wood and her colleagues at Kings College, London, reported these findings in the August issue of Environmental Microbiology. The odour-eating methylotrophic bacteria were isolated from the tongue, tooth plaques (supra-gingival plaques) and gum edge (sub-gingival plaques) of volunteers. They include strains of Bacillus, Brevibacterium casei, Hyphomicrobium sulfonivorans1, Methylobacterium, Micrococcus luteus and Variovorax paradoxus.

The composition and function of bacterial flora of the mouth have been extensively studied in the past, but until now it was not recognised that methylotrophic bacteria are part of the normal oral microbial environment or 'microflora'.

The researchers found no difference between strains of bacteria found in the mouths of healthy volunteers and those suffering from progressive gum disease (periodontitis), a condition which is often associated with smelly breath. However, no assessment was made of the levels of methylotrophic bacteria present, low levels of which may be associated with bad breath.

In a previous paper, Dr Wood et al found that the foot is also a source of methylated sulphides and strains of these odour eating bacteria, including Brevibacterium and Methylobacterium, which are also part of the normal foot microbial flora.

The results of this study will assist future investigation into the detection of the levels of methylotrophic bacteria and their possible relationship with the oral concentrations of methylated sulphides. This may lead to a natural way of reducing smelly breath and feet.


Notes to Editors:
1. An image of H. sulfonivorans is available on request from Lucy Mansfield at Blackwell Publishing
2. To view the full article, please follow these simple instructions:

    A. Go to
    B. If you have already registered, enter your Username and Password at the top of the page and click on Login. Go to step D.
    C. If you have not yet registered, click on Register at the top of the page and complete the form. Please make a note of your Username and Password for future use.
    D. Click on the My Synergy tab at the top of the screen, and then click on the Access tab.
    E. Enter the following code in the Access Token field, exactly how it appears here: EMI July 2005
    F. Click Continue
    G. You have full access to the article listed above.

3. Articles details: Isolation and molecular detection of methylotrophic bacteria occurring in the human mouth Vasiliki Anesti, Ian R. McDonald, Meghna Ramaswamy, William G. Wade, Donovan P. Kelly, Ann P. Wood, Volume 7, Issue 8, Page 1227-1238, Aug 2005 Molecular detection and isolation of facultatively methylotrophic bacteria, including Methylobacterium podarium sp. nov., from the human foot microflora, Vasiliki Anesti, Jyotsna Vohra, Shalini Goonetilleka, Ian R. McDonald, Bettina Sträubler, Erko Stackebrandt, Donovan P. Kelly, Ann P. Wood, Volume 6, Issue 8, Page 820-830, Aug 2004
4. If you would like to arrange an interview with the authors, please contact Dr Ann Wood,
5. Environmental Microbiology is published by Blackwell Publishing with the Society for Applied Microbiology. The journal is devoted to the study of microbial processes in the environment, microbial communities and microbial interactions.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.