Not all Probiotic bacteria are the same...
Not all friendly bacteria, or even all strains of each culture, bring the same beneficial effect to the consumer.
Different Lactobacilli strains have different characteristics and very different survival/reproductive capabilities when in the hostile environment of the human GI system.
Lactobacillus acidophilus & Bifidobacterium bifidum are natural, indigenous inhabitants of the human GI system.
Lactobacillus bulgaricus & Streptococcus
thermophilus are transient visitors to the GI
tract. L.b bacteria do not colonize in the GI
system but greatly help other friendly bacteria
to survive and multiply.
Some studies show that introducing
transient bacteria such as L.b & S.t to the GI
tract is more beneficial than just adding to the
existing acidophilus & bifido because they
so clearly improve the long term health and
number of those indigenous bacteria.