There are 6 strains in the probiotics: Lactobacillus acidophilus DDS - 1 Lactobacillus reuteri Bifidobacterium bifidum Bifidobacterium breve Bifidobacterium lactis Bifidobacterium longum (ora.organic)
However, some research published in 2013 showed that glycopolymers from a B. bifidum strain interact with autoimmune thyroid antibodies. (powerofprobiotics.com)
When you were born, the B. bifidum strain was already present in your intestines, protecting you from germs. (globalhealingcenter.com)