Lactose is broken down and converted into lactic acid when bacteria is introduced such with yogurt and sour cream. People can usually eat yogurt without any problems.
Cheese tolerance is somewhere in the middle.
The lactobacteria responsible for acidifying milk is naturally in the raw product. Acidified milk is not hospitable to the bad strains of bacteria that cause food born illness. Pasteurizing destroys the natural beneficial lactobacteria.
Raw milk need not be innoculated... it’s just a time issue. I have opened sealed and refrigerated bottles of raw milk 3 months past it’s “expiration date”... the cream on the top is literally sour cream. The skim milk is like buttermilk.