When is a Multi-Strain Probiotic a Good Idea?

You may have heard probiotics can provide a multitude of beneficial effects, but how do you know which one to choose when you’re confronted by a countless range of options? What probiotic will help your presentation? Do you need a product with one probiotic strain or multiple probiotic strains?

With all the choice, it easy to feel overwhelmed and confused about which probiotic is right for you. To help guide your decision consider these two main options: single or dual strain formulas are usually designed to address specific conditions, while multi-strain products, containing more than four strains, are normally aimed at supporting general and digestive health.

This article focuses on choosing the right multi-strain probiotic for your needs, as the more strains a product contains, the greater the chance for variability in its medicinal effect. So, to help you confidently select the right multi-strain for you, ensure each of your available options can answer these four questions below:


Number 1:  Is it strain specific?

While greyhounds and dachshunds are both species of dog, I think you’d agree they’re very different in their characteristics. Probiotics are just the same – whilst all the bacteria in your probiotic bottle will come from similar genetic origins, each organism is unique, and carries its own traits and health benefits.

In other words, just as all dogs are derived from the same genus and species, with each breed being different, two probiotics can be of the same genus and species, but their characteristics also vastly different when it comes down to the particular strain.[1]

It’s easy to tell the difference between different dog breeds, but the only way to know what specific probiotic bacteria is present in a formula is if its strain is listed, not just the genus and species. To use Lactobacillus acidophilus NCFM® as an example, Lactobacillus is the genus, acidophilus the species and NCFM® the strain. Unfortunately, it’s very common to only see the genus and species (e.g. Lactobacillus acidophilus) on a probiotic label, leaving the specific action of probiotic strain in question.

Not knowing a probiotics strain is akin to knowing you’re being given a puppy, but nothing more. As all probiotics behave differently, if the strain hasn’t been listed, you cannot be sure the health claims on the label are associated with the multiple probiotics in the bottle.


Number 2: Is there high quality evidence in humans?

Another important factor is the amount of evidence that exists to support a probiotic’s effect in humans. This is a critical point as research conducted solely in laboratories or animal models does not always give the same results in humans.[2]

To be confident your multi-strain probiotic will provide the expected health benefits, ensure all of the strains within the formula are supported by human research. For example, highly researched organisms, Saccharomyces cerevisiae (boulardii) and Lactobacillus rhamnosus LGG® have both been shown to reduce antibiotic related side effects in large human trials.[3],[4]  This means that they are more likely to produce their expected outcome, as the research has robustly shown their benefits.


Number 3: Does the dose match the science?

Although a multi-strain probiotic may contain proven strains, if the amount on the label doesn’t match what has been validated in the research, it may fail to deliver the expected benefits. Different doses of probiotic strains have been found to have different effects, and whilst an effect may not be undesirable, it may not be intended result you were wanting.

For instance, if research shows a medical effect of a probiotic at 10 billion CFU (colony forming units, or live bacteria), but the product instead contains 250 million, obtaining the same effect at this different dose is highly questionable. As such, asking for any supportive product literature can help you determine if the probiotic contains the correct dose for your desired effect.


Number 4: Does it match your presentation?

If a product lists the strains used, has human evidence and uses them at the researched dose, your final question to ask is – does the evidence match what you want to use it for?  You’re more likely to see your desired health benefits if you use probiotics with evidence for your condition or symptoms. For example, at a dose of 50 billion CFU, Lactobacillus rhamnosus HN001™ has been shown to increase immune activity,[1],[2] however if you’re wanting a formula to address symptoms of irritable bowel syndrome, that specific probiotic may not be suitable for your current needs.

Don’t be afraid to ask for more information so you can consider if a product will address your specific issues. I will be able to take you through the evidence and applications for different probiotic products.


Taking a multi-strain probiotic is a great way to maintain the health of your digestion and overall wellbeing. However, with all the choices available, it’s important to purchase a product you can trust and rely on. For this, I’d recommend keeping these four points in the forefront of your mind so you can make your next probiotic purchase with unwavering confidence. Remember, not all probiotics are created equal, but that doesn’t mean that you have to be left in the dark when it comes to making the right choice.


[1] McFarland LV, Evans CT, Goldstein EJC. Strain-Specificity and Disease-Specificity of Probiotic Efficacy: A Systematic Review and Meta-Analysis. Front Med (Lausanne). 2018 May 7;5:124. doi: 10.3389/fmed.2018.00124.

[2] Pound P, Bracken MB. Is animal research sufficiently evidence based to be a cornerstone of biomedical research?. BMJ. 2014 May 30;348: 3387. doi: https://doi.org/10.1136/bmj.g3387

[3] Szajewska H, Kołodziej M. Systematic review with meta-analysis: Saccharomyces  boulardii in the prevention of antibiotic-associated diarrhoea. Aliment Pharmacol Ther. 2015 Oct;42(7):793-801. doi: 10.1111/apt.13344

[4] Szajewska H, Kołodziej M. Systematic review with meta-analysis: Lactobacillus  rhamnosus GG in the prevention of antibiotic-associated diarrhoea in children and adults. Aliment Pharmacol Ther. 2015 Nov;42(10):1149-57. doi: 10.1111/apt.13404.

[5] Sheih YH, Chiang BL, Wang LH, Liao CK, Gill HS. Systemic immunity-enhancing effects in healthy subjects following dietary consumption of lactic acid bacterium Lactobacillus rhamnosus HN001. Jour Am Coll Nutr 2001: 20 (2); 149-156

[6] Gill HS and Rutherfurd KJ. Probiotic supplementation to enhance natural immunity in the elderly: effects of a newly characterised immunostimulatory strain Lactobacillus rhamnosus HN001 (DR20™) on leucocyte phagocytosis. Nutr Res 2001: 21; 183–189