Dr. Greene's Answer
I’m a big fan of nursing moms taking probiotics because many studies have shown benefits to babies’ immune systems. Most of these studies have used a strain of probiotic called LGG (found in a product called Culturelle). It may prove that a product with more strains or higher culture counts would be even more effective.
Not only do probiotics pass through into breast milk, they can usually be given directly to babies as well for similar beneficial effects.
We all used to get more beneficial bacteria in our diets before pasteurization and sterilization of food (something that can be especially important for safety when food comes from overcrowded farming operations, travels great distances, or needs to stay fresh a long time).
We benefit from regular exposure to beneficial bacteria — and all the more so in certain situations, such as when a baby needs to be treated with antibiotics.