I should probably look into this more, but I think quite often they pasteurize the product, then put approved bacteria cultures back in. Some dirt and (animal)

I should probably look into this more, but I think quite often they pasteurize the product, then put approved bacteria cultures back in. Some dirt and (animal) digestive tract bacteria is fine, but some is not, so I'm not sure companies would let random stuff grow in their products even just for QA reasons. How would they give you a number of bacteria CFUs if they got in from floor dust and fecal contamination?