How Important is it to have "Human Strain" Probiotics?

“Human Strain” Probiotics

The origin of a strain simply specifies from what source that particular strain - often part of a blend - was first isolated. Its origin is related to establishing intellectual property and a chain of custody, but not to any possible health benefits. There are all kinds of organisms, both desirable and undesirable, in our guts, but microbiologists do not consider the first identified/isolated source to be predictive of the health benefits that any particular strain (substrain) will provide to people.

So touting a “human source” or “soil organism” is actually a marketing game, not a valid scientific argument, and in fact is an anti-scientific message. Just because an organism was obtained from human feces (or rarely, saliva), perhaps because the person actually obtained it by eating fermented foods or even from contact with soil, doesn’t mean that it has probiotic properties…or even different properties than eating it in that yogurt or directly consuming those soil organisms. We all probably have some small quantity of E coli and Salmonella in our bowels; should they therefore be promoted as “human strain” probiotic bacteria? Obviously not…

In the scientific literature the benefits of a probiotic strain (or blend) depends solely on its technical qualities: proper identification of the specific strain (substrain), its stability in a consumer product, its bile and acid resistance, its ability to colonize and persist in the human GI tract, and any specific health effects it provides as measured in both test tube and human clinical trials when given to a human being. None of these qualities depend on its original sourcing. Specific label claims relating to substrains of probiotics depend totally on the body of clinical evidence of how that substrain provides benefits to people.

Look for the addition of a third name to the Latin binomial (2-word Latin name) of a strain to indicate a specific substrain, as in “Lactobacillus acidophilus La-14” or “Bifidobacterium lactis BL-04”.

If a company is touting the origin of their strain(s) rather than their proven clinical health benefits, then they may have no clinically validated strains and are just trying to promote theoretical rather than demonstrated benefits. Why would they promote strains based on irrelevant historical factors related to the strain's discovery rather than providing evidence of their product's demonstrated health benefits if they do have clinically relevant strains?

Smart consumers will look for evidence-based label claims, such as clinical trials utilizing their particular strain to assure that a probiotic product will have some credible evidence of being health promoting.