Do they always need to add a base? if the probiotic is freeze-dried, why is a base needed?
For one thing we cannot see the bacteria with the naked eye. So without a base the capsules of probiotics would look empty.
But the bases also allow the product to flow through the machinery properly for capsuling, tableting or bottling. Imagine trying to run bacteria, that clings to surfaces, through a capsuling machine. It simply would not work.