How to choose a probiotic

Posted on Wed, 11 Feb 15

Probiotic supplements are very popular but the wide range available can make it difficult to identify a quality and effective product. The following simple guide can help you.

Probiotics are defined as live micro-organisms (mostly bacteria, and some yeasts), which, when taken in adequate amounts, can confer health benefits.

And certain probiotics have shown promise for illnesses as diverse as digestive problems, allergic disease, respiratory infections, mental health and weight loss. But not all are effective, and in some cases you may be simply paying for expensive bacteria.

When choosing a probiotic it will help you to consider the following:

Label

Probiotic bacteria should be labeled according to their genus (e.g. Lactobacillus or Bifidobacteria) species (e.g. acidophilus or rhamnosus) and strain (e.g. La-1, NCFM, or GG). For example; Lactobacillus rhamnosus GG.

This is because different strains of bacteria can have very different health effects even if they are the same genus or species. Accordingly, the strain identification can help you choose a product that provides bacteria that has been shown to have a probiotic effect (survive digestion and improve your gut bacteria) or a particular health benefit.

The label should also provide the amount of bacteria per dose, expressed as CFU (colony forming units, or number of bacteria) as well as an expiration date and storage instructions.

Safety

Although probiotics have an excellent safety profile, care should be taken if considering probiotics in newborns, people who are immunocompromised and in people with severe underlying illness. In these cases it is best to speak to a health professional before use. Manufacturers should be able to provide you with the details of safety assessments that have been conducted on their products and any warnings or contraindications.

Efficacy

Not all probiotics are effective. For example, in the treatment of irritable bowel syndrome (IBS) only a few products have been found to improve overall symptoms, while others may alleviate only individual symptoms such as bloating. Results of other studies have found no benefit at all of certain products.

Regulatory restrictions on therapeutic claims and product marketing can make it very difficult to identify a probiotic with evidence of efficacy for a particular use. But identifying a specific product that provides a strain or number of strains that have supporting research, or evidence-based health claims can help. You could also speak to a health professional who is familiar with evidence-based probiotics.

Multi-strain vs. single strain

It has been suggested that a multi-strain probiotic mixture could be more effective due to a broader spectrum of action than that provided by a single strain. However, current research does not conclusively support this. Evidence that a product is effective, such as a clinical study, is a better guide than the number of different bacteria it provides.

Dose

A higher strength does not mean a product will be more effective, and very few products have been studied at different strengths to determine an optimal dose. In research studies some probiotics have been shown to be effective at as little as 50 million CFU per day while others as much as 900 billion CFU. And the dose chosen for research may simply be a best guess.

Thus there is no optimal or general recommended dose for probiotics. Choosing a product that provides a daily dose that reflects the same dose used in human clinical research on the probiotic strains it provides is the best way to ensure a particular product is effective.

Storage

The storage of probiotics varies with some needing to be refrigerated while others have good stability at temperatures around 25-30 degrees. Follow the storage instructions on the label. Manufacturers should be able to provide stability studies on request. If you live in a warm climate it is best to keep probiotics in the fridge to ensure their potency.

Price

Cost differences can vary considerably; by as much as 300% for a daily dose of a product that will do essentially the same thing. And products with evidence of beneficial effects may be cheaper than unproven products. First find a few good products, and then divide the product price by the number of daily serves it provides to compare the daily cost.

Yoghurt

Yoghurt can be made with acidophilus but the types of bacteria used to turn milk into yoghurt are often not the same strains of bacteria shown to have probiotic health effects. And research has shown that yoghurt cultures die off quickly after manufacture and may not influence your gut bacteria at all. Thus, it is incorrect to refer to yoghurt cultures as probiotics unless they have been demonstrated to have a probiotic effect.

However, some yoghurt’s have added probiotics and well established benefits. Look for yoghurts with added probiotic strains; these will normally be stated in the nutrition information on the label. But beware the “health halo,” just because a food has added probiotics does not mean it's healthy.

References:

Sanders ME, Guarner F, Guerrant R, Holt PR, Quigley EM, Sartor RB, Sherman PM, Mayer EA. An update on the use and investigation of probiotics in health and disease. Gut. 2013 May;62(5):787-96.

Sanders, ME. How Do We Know When Something Called “Probiotic” Is Really a Probiotic? A Guideline for Consumers and Health Care Professionals. Functional Food Reviews, Vol 1, No 1 (Spring), 2009: pp 3–12

Quigley EM. Probiotics in the management of functional bowel disorders: promise fulfilled? Gastroenterol Clin North Am. 2012 Dec;41(4):805-19.

Chapman CM, Gibson GR, Rowland I. Health benefits of probiotics: are mixtures  more effective than single strains? Eur J Nutr. 2011 Feb;50(1):1-17.

Shah, NP, et al., 1995. Survival of Lactobacillus acidophilus and Bifidobacterium bifidum in commercial yoghurt during refrigerated storage. International Dairy Journal 5, 515–521.

del Campo R, et al. Scarce evidence of yogurt lactic acid bacteria in human feces after daily yogurt consumption by healthy volunteers. Appl Environ Microbiol 2005;71:547–9.