It's important to make sure it's Lactobacillus rhamnosus GG (LGG).
"Some strains of Lactobacillus rhamnosus are radically different. So although all L. rhamnosus strains have many things in common, some of them are different enough to have different effects in your body. If you desire a particular effect, be certain to get the correct strain. Some of the most researched strains are listed below:
L. rhamnosus GG, also known as "LGG"
L. rhamnous GR-1
L. rhamnosus HN001
L. rhamnosus DR20
HOWARU rhamnosus
L. rhamnosus ATCC 7469"