I baked my own bread. Basically anything high in fiber and hard for your body to digest has a lower GI. These breads are good in that if you only like white bread then they can satisfy you. If you are into whole wheat then you are already getting a lower GI breaed provided it's not slammed with glucose, high fructose or any other nasty -ose you don't need.
Good bread has only a few things in it: yeast, flour and it's varients, a small amount of sugar/honey/syrup to feed the yeast and make it happy, small amount of salt (which you can leave out) and that's it. You can add a small amount of fat in the form of oil or butter and milk to make it longer lasting our smooth the texture of the crumb.
If your bread has anything other than these key ingredients then seriously consider switching to one that does. It's like all those polysorbate 80 thingies in food and E-whatevers.
Look for flax seed as it has a low GI and unless it's ground your body just passes it whole. In Spain it's eaten by teaspoons to alieviate constipation.
Also spelt and soya and rye are brilliant low GI flours.
Sorry... hijack over... you can tell I love my bread... have a sesame, whole wheat, white, spelt and poppy seed one rising as we speak.
Still though... moderation is important.