They probably contain a sugar alcohol eg maltitol. There is always a debate about how much these impact insulin - if you search online for brand and net carbs it will tell you the correct carb count. Given they are probably teeny, then i would just take the full carb count to be safe.
However warning 1) some people react with a stall even with sugar alcohols
2) might trigger cravings
3) they can have very unfortunate effect on insides!