The tongue microbiota of low odour and malodorous individuals

Abstract

The tongue bacterial microbiota of 50 individuals was identified and enumerated to group or genus level. Possible relationships between these data and the oral malodour status of each individual were explored. When subjects were grouped into low or high odour producers, significant increases in the total bacterial load and key bacterial groups, namely gram-negative anaerobes, which include Porphyromonas/Prevotella species and fusiforms, were related to high odour. However, on an individual basis the extensive variation between subjects reduced the correlation between bacterial groups and odour. Two phenotypic characteristics of the microbiota, volatile sulphur production and proteolytic activity, were also assessed. These were strongly associated with odour; in particular, the proportions of hydrogen sulphide producing organisms were significantly related to the odour levels of the individuals, despite the interpersonal variation. Thus it appears that it is the metabolic activity of the mixed microbiota rather than the bacterial load, or genus types present, that most contributes to oral malodour.