IMPLICATIONS OF RESOURCE-RATIO THEORY FOR ORAL MICROBIAL ECOLOGY

The ability to compete for the limited nutrients available to the micr oorganisms of dental plaque is a strong ecological determinant of the structure of the subgingival ecosystem. This paper introduces a new co ncept from the field of ecology, resource-ratio theory, and applies it to the dynamics of microbial dental plaque with emphasis on the putat ive periodontal pathogens. Resource-ratio theory is a mechanistic theo ry of resource competition that utilizes pairs of growth-limiting nutr ients in a stoichiometric fashion to predict zones of competitive domi nance, exclusion, and coexistence for organisms competing for these re sources. Once these resource pairs are identified for plaque organisms , resource-ratio theory may provide predictions of changes in the micr obial community structure of plaque based on directional changes in th eir resource supply ratios.