You might also want to include high quality probiotic supplement in your diet. (supernutritionlife.com)
It is therefore very beneficial for those who want to prevent or increase B12 levels to take good quality probiotic supplements containing the above mentioned strains. (fullhealthsecrets.com)
As a comparison, some of the highest quality probiotic supplements out there, contain 50 billion per serving (1 capsule / serving, typically). (healthbean.ca)