In the body, iodine has antibacterial, antiviral, antifungal, antimicrobial, antiparasitic, antiproliferative, antitumor, and apoptotic properties, but they are targeted. In-other-words, unlike a broad spectrum pharma antibiotic, which will devastate both good and bad bacteria, iodine affects only the bad bacteria because, unlike pharma antibiotics which work directly on bacteria, iodine is used by the body to battle the bacteria the body deems appropriate to "attack".

More iodine info at health101.org/iodine