Friday, May 25, 2018

Probiotics - What You Need to Know

Should I take probiotics? Which one should I take? The higher the number, the more effective it is right? These are questions that community pharmacists are posed with daily.
Probiotics are defined as “live microorganisms, which when consumed in adequate amounts, confer a health effect on the host”.

Lactobacillus and Bifidobacterium are the most common bacteria found in the probiotics on your local pharmacy’s shelves. These two species differ in benefits, and even different strains within the same species can diverge

Lactobacillus Bifidobacterium
  • Inhibit growth of enteric pathogens
  • Produce antimicrobial compounds
  • Reduce inflammation
  • Inhibit growth of enteric pathogens 
  • Aid in lactose maldigestion 
  • Modulate the immune system 
  • Reduce allergy symptoms 
  • Hepatic encephalopathy

Probiotics are not equally created

There are many probiotic formulations on the market and they differ in several aspects including: composition, manufacturing, production, shelf life, strength of the formulation (measured in Colony Forming Units – CFUs), ability to deliver to the gut, clinical evidence and Health Canada approved indications.1

  • CFU refers to the number of viable (able to multiply) bacteria cells in a sample 
  • A minimum number of microorganisms must be delivered to the gut in order to have the intended health benefits 
  • E.g. A minimum of 10 billion CFU is required to reduce the risk of CDAD
Ability to deliver to the gut3,4
  • To bestow its clinical effects, the probiotic must be able to deliver to the gastrointestinal system.
  • Enteric coated probiotic capsules have shown to be the most effective in reaching the gut. Encapsulated and probiotic powders have limited resistance to stomach acid
  • Evidence from one US review suggests that there is a 20-40% survival rate of bacteria through the GI tract.
  • However, this same review also stated that there is no evidence that orally administered probiotic organisms adhere to intestinal cells – they seem to pass into the feces without adhering or multiplying. This implies, to construe benefit, the probiotic must be administered continuously.
  • Temperature variations and other environmental conditions can compromise the stability and viability of the bacteria
  • Some products make no claim at all, while others claim the amount only at the time of manufacture. Some products, such as capsules, require the bacteria to be freeze-dried and such processes may also affect viability.
  • One US study conducted by found that among 26 probiotic products, eight contained less than 1% of the claimed number of live bacteria or of the claimed minimum of 1 billion.5
  • Consumers may be misled, as the number of live bacteria in a probiotic at the time of purchase may be lower than the labelled amount

So what’s the evidence?
Working in a community pharmacy, I’ve heard indications ranging from allergic conditions to vaginal yeast infections, but most commonly, and where most of the evidence lies, is with antibiotic use and diarrhea. Some probiotics can prevent diarrhea associated with antibiotic use (AAD) and can reduce the risk of Clostridium difficile associated diarrhea (CDAD).

Health Canada lists over 1000 types of active probiotics on the market but only 15 are indicated for AAD management and/or prevention, and only one probiotic is approved for both AAD and CDAD. This just goes to show probiotics are not interchangeable and can have great disparity.

There are no probiotic containing foods (e.g. yogurt) that have approved health claims. The CFU count in these foods generally do not contain the minimum of 10 billion CFUs to confer health benefits. In addition, the ability of food to deliver bacteria to the gut has not been clinically studied.4

Five Key Criteria for Recommending an Effective Probiotic6
  1. Identifiable high-quality strains
  2. Synergy of strains
  3. Guaranteed bioactivity (live, health microorganisms)
  4. Gastrointestinal survival
  5. Clinical studies (on the finished product).
What do you tell your patient?6
  1. Not all probiotics are the same
  2. Select a specific and appropriate probiotic for intended effect. Refer to the Canadian guide to probiotic products if you are unsure what to recommend
  3. Always select a product with the highest level of evidence, especially look for those approved by Health Canada for specific indications
  4. Advise patients to take probiotics at least 2 hours apart from antibiotics (if AAD/CDAD is the indication)
All in all, probiotics can be used to support a healthy digestive tract and immune system but not all probiotics can be assumed to provide the same efficacy for other indications.

Final Thoughts: 
Only recommend products approved by Health Canada and do your research before prescribing. Health Canada approved labelling should be printed clearly on the packaging and should be searchable on Health Canada’s Licensed Natural and Non-prescription Health Products Database (LNHPD) using the product’s unique NPN number. For general information on the use of probiotics, Health Canada provides a useful guide that outlines acceptable claims and identifies the strains that have been most studied.7

If you’d like to learn more about Probiotics in AAD and CDAD – visit rxBriefCase for the program:

  1. Joint FAO/WHO Expert Consultation on Evaluation of Health and Nutritional Properties of Probiotics in Food Including Powder Milk with Live Lactic Acid Bacteria, October 2001. 
  2. Goldenberg JZ, Ma SSY, Saxton JD, Martzen MR, Vandvik PO, Thorlund K, Guyatt GH, Johnston BC. 2013. Probiotics for the prevention of Clostridium difficile-associated diarrhea in adults and children. Cochrane Database of Systematic Reviews.5:CD006095. 
  3. Grzeskowiak et al. 2011. Manufacturing process influences properties of probiotic bacteria. Br J Nutr. 105 (6): 887 -94
  4. Millette M et al. 2013. Gastrointestinal survival of bacteria in commercial probiotic products. International Journal of Probiotics & Prebiotics. 8 (4):149-56
  5. Mason, P. 2007.Probiotics: are they worth taking? The Pharmaceutical Journal (Vol 278)
  6. Probiotics: A Leading Role in Reducing the Risk of Antibiotic Associated Side Effects & C. difficile Associated Diarrhea;
  7. Doran S, Snydman DR. Risk and safety of probiotics. CID 2015; 60 (Suppl 2): S129-S134.