[Excerpt]
The different forms of iodine also matter. Pure iodine kills all kinds of bacteria but it also gets changed to iodide as it interacts with things in the gut. This severely limits the ‘damage’ it can do. Though, taking too much pure iodine would be very bad for your stomach as it would simply kill as much bacteria as it comes into contact with. Pure iodine helps control bacteria and prevent overgrowth but it has the potential to also do damage.
[Full Article]
https://myzenhaus.com/iodine-gut-bacteria-probiotics-stomach/