Lactobacillus rhamnosus, so-called because it can ferment the unique sugar, rhamnose, was initially isolated from a human. This is an essential fact that is often overlooked in crafting probiotic preparations: If a microorganism was initially harvested from a human, it suggests that the organism has the potential to colonize the human gastrointestinal tract and proliferate in that unique environment. Too many bacteria promoted as probiotics do not have the capacity to colonize the human gastrointestinal tract and disappear within days to weeks of ingestion. It does not necessarily mean that transient residence of a bacteria is of no benefit, but it means that, in order to obtain long-term benefit, regular and repeated intake is necessary. Doesn’t it make more sense to recolonize the gastrointestinal tract with bacterial species that can colonize and proliferate, thereby perhaps even providing a foundational role in supporting the colonization and proliferation of other bacterial species? There may be variation, even within the same species and strains, to colonize the human gastrointestinal tract, but L rhamnosus has at least the theoretical potential to do so.
We also must pay attention to the strain of bacteria due to the issue of strain specificity. To illustrate: You have E. coli in your gut, your family has E. coli in their guts, most humans have E. coli. But consume, say, Romaine lettuce contaminated by cow manure with the O157 strain of E. coli and you can die of kidney failure, sepsis, and dehydration—same species, different strain. Strain can therefore literally mean the difference between life and death. Or it can mean that L. reuteri DSM17938 can provoke oxytocin release from the hypothalamus, but another L. reuteri strain cannot. Yet many clinical studies do not even specify the strain used nor do many probiotic manufacturers specify strains on their product labels—major oversights.
The L rhamnosus strain that has been most studied is GG (ATCC 53103), so let’s focus on this strain. This strain compared to other L. rhamnosus strains has been demonstrated to be more adherent to the mucous lining of the intestines, more tolerant to the harsh environment of the human gastrointestinal tract (e.g., stomach acid, bile), and has the ability to colonize other parts of the body such as the mouth, upper airway, vagina, as well as the colon.
Among the benefits of L. rhamnosus GG that have been charted in humans are:
- Reduced eczema skin rashes in children
- Abbreviated course of infectious diarrhea at a dose range of 1-10 billion CFUs per day
- Reduced food allergies/hypersensitivity in children
- A broad spectrum of anti-inflammatory effects
- Reduced likelihood of upper respiratory infections (e.g., sinusitis and bronchitis) with 1 billion CFUs
- Reduced potential for proliferation of bacterial pathogens in the gastrointestinal tract
- Increased effectiveness of vaccines for flu, polio, and pneumococcal pneumonia with a dose range of 1.8-10 billion CFUs per day
- Protection of the intestinal lining against injury and enhanced mucous production
Because of L. rhamnosus’ clear-cut benefits on reducing diarrhea, it is increasingly being used as an adjunct to various cancer and HIV therapies.
It is therefore worth choosing a probiotic with L. rhamnosus GG among the strains contained but, as mentioned, most brands fail to specify strain. Among the few ways to obtain L. rhamnosus GG should you wish to include it is:
SuperSmart Lactobacillus rhamnosus GG 10 billion CFUs. This probiotic contains L. rhamnosus only.
Lifted Naturals with a total of 30 billion CFUs of 6 species/strains, of which L. rhamnosus is present at an unspecified amount.
However, unless you are intent on obtaining one or more of the benefits listed above, I discuss this and other species/strains not so that you go out and buy this or that probiotic, but to raise awareness of the power of probiotics, ask whether this or that strain should be a component of the probiotic preparations we choose or whether we should add it to a mixed-culture yogurt (along with, say, L. reuteri, L. acidophilus, L. bulgaricus, and Streptococcus thermophilus), and whether we can, over time, construct a menu of what I call “foundational microorganisms that, when restored, are self-propagating and support the growth and proliferation of numerous other desirable species. As our discussions unfold, we shall be creating a menu of essential species and strains that should be included in your microbiome efforts. In short, it is a work in progress with plenty more to come.