These changes may increase pathogenic organisms or their activity causing a series of oral infectious diseases such as dental caries or periodontal diseases.

这些改变可能会增加致病微生物的数量或提高其活性，从而导致诸如龋齿、牙周疾病等一系列口腔感染性疾病。

You have something much worse: periodontal disease.

你有更糟糕的事情：牙周病。

Animals as adults commonly get periodontal disease, so we really should be brushing their teeth, and more pet owners are starting to do this.

成年后的动物通常会患牙周病， 所以我们真的应该给它们刷牙，而且越来越多的宠物主人开始这样做。

This alteration can disrupt the bacterial equilibrium in the oral cavity by increasing harmful bacteria and decreasing the beneficial ones, thus leading to a series of oral infectious diseases such as dental caries, or periodontal diseases.

这种改变会增加有害菌、减少有益菌，从而破坏口腔中的细菌平衡，导致龋齿、牙周疾病等一系列口腔感染性疾病的发生。