(IMAGE) Tokyo Medical and Dental University Caption The bacterial activity of a healthy site was defined as 1. The activities of several taxa were higher than that of red complex bacteria (e.g., Porphyromonas gingivalis). Credit Department of Periodontology, TMDU Usage Restrictions None License Licensed content 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.