▲ 662 r/explainlikeimfive
ELI5: Why is dietary fiber good for you, but the inability to digest other things (i.e. lactose intolerance) results in digestive issues?
As I understand it, dietary fiber is essentially cellulose and other large carbohydrates that the human digestive system is incapable of breaking down; as a result, it helps with bowel movements, feeds your gut microbiome, etc etc.
However, in the case of a condition like lactose intolerance, it is simply another nutrient that the body isn’t able to digest—but this results in bloating, gas, cramps, and even diarrhea.
Why is this? What is the physiological mechanism at play that makes it so not digesting cellulose is a good thing for your body, but not digesting lactose is a bad thing?
u/FerfyMoe — 5 days ago