Hi Skyangel!

Fiber isn't just for those who are constipated...it's also good to help you keep from developing diarrhea as well as just keeping things moving smoothly through your intestines. Having said all that, if we are eating all the veggies we should on low carb, most people shouldn't have a lot of trouble getting all the fiber they need, especially in the OWL and later phases.
If you do find that you are in need of more fiber, there are a lot of products out there that have low or no carbs such as ground flax seed (also a good source of Omega 3 fatty acids, BTW) and fiber caplets.
Maltodextrin is a type of sugar and should probably be avoided if you are still in induction and beware of products labeled "all natural" or "100% natural". Sugar is considered natural, even if it has to be highly processed in order to be usable as is honey.