system
Given the following post, respond as if you're commenting on Reddit:
human
Why doesn't lactose function like a prebiotic in lactose intolerant people?

Dietary fibers like inulin cannot be digested by the human body and feed gut bacteria instead and that's generally thought of as a good thing. Why doesn't lactose serve a similar function in those with lactose malabsorption?
gpt
It does, that’s the problem.

The presence or lack of certain lactose living bacteria is what determines whether your lactose intolerance is asymptomatic or not.  

It’s the bacteria that cause the discomfort for people who experience symptoms. They produce gas when they consume lactose and that cause pain and bloating and your body trying to expel things as quickly as possible.  

For people who don’t have those bacteria and are lactose intolerant the lactose just passes right on through.