I think it kills bacteria and boosts the immune system, which would improve all functions of the body. I had several abscessed tooth roots for over ten years and OP seems to have killed the bacteria in those infections within a few weeks for the most part. Infections made my gums sensitive and somewhat sore in spots, but that's all gone. I did just have another toothache after 2 months of OP, but I think it was a lingering pocket of bacteria saying good-bye. I wouldn't be surprised to have one or more additional healing crises, but hope that's it.