
Originally Posted by
BestBetter
There are two types of fiber: soluble and insoluble.
Soluble fiber is the 'good' fiber. This type of fiber can be digested, and supports the probiotic gut flora. Examples of soluble fiber are things like apple and potato (without the peel).
Insoluble fiber is the type that is very irritating to the digestive system because it can not be digested since we don't produce the enzyme, cellulase, which is required to break it down. Since we must rely on our gut bacteria to ferment this type of fiber, eating excessive amounts of it often causes bloating and inflammation, due to the gas build-up from the fermentation in the gut.
Vegetables are primarily made of cellulose, which is insoluble fiber. With certain types, you can reduce this by peeling and deseeding them, or running them through a juicer to separate the fiber or cooking them, but others you just have to accept that you might not be able to eat as much of them if you want to heal.
Grains and legumes are problematic because the outer coating generally contains insoluble fiber (much like the peel of vegetables and fruits), which can't be easily separated. White rice, for example, has had the outer germ layer removed, so it doesn't contain this problematic insoluble fiber (nor the anti-nutrients).