Lactobacillus rhamnosus GG is classified as a strain from the Lactobacillus rhamnosus species. Lactobacillus rhamnosus GG is often referred to as Lactobacillus rhamnosus LGG® depending on probiotic manufacturer, the strains are identical.
This particular strain, L. rhamnosus GG, has had extensive attention and analysis in the field of probiotics. To date, it has been the subject of over 250 clinical studies, with around 40 of those involving paediatric subjects. As documented on clinicaltrials.gov, it holds the distinction of being the most thoroughly studied probiotic strain in the world (Dronkers, Ouwehand, and Rijkers, 2020).
In April 2020, there was a taxonomic update, and L. rhamnosus has been renamed Lacticaseibacillus rhamnosus. Therefore, the complete designation of the strain is now Lacticaseibacillus rhamnosus GG (Zheng J et al., 2020).
Use this link for a detailed review - Lactobacillus rhamnosus GG : A Review of Clinical Use and Efficacy