THE TONGUE MICROBIOTA OF LOW ODOR AND MALODOROUS INDIVIDUALS

The tongue bacterial microbiota of 50 individuals was identified and e numerated to group or genus level. Possible relationships between thes e data and the oral malodour status of each individual were explored. When subjects were grouped into low or high odour producers, significa nt increases in the total bacterial load and key bacterial groups, nam ely gram-negative anaerobes, which include Porphyromonas/Prevotella sp ecies and fusiforms, were related to high odour. However, on an indivi dual basis the extensive variation between subjects reduced the correl ation between bacterial groups and odour. Two phenotypic characteristi cs of the microbiota, volatile sulphur production and proteolytic acti vity, were also assessed. These were strongly associated with odour; i n particular, the proportions of hydrogen sulphide producing organisms were significantly related to the odour levels of the individuals, de spite the interpersonal variation. Thus it appears that it is the meta bolic activity of the mixed microbiota rather than the bacterial load, or genus types present, that most contributes to oral malodour.