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With Probiotic Supplements, Is There Truth in Labeling?

By Carrie Dennett, MPH, RDN, CD

Gut health is a major buzzword, and probiotics are a part of that, especially as research uncovers more about how a balanced intestinal ecosystem can keep our gut, and us, healthier.

Probiotics are live bacteria and/or yeasts that confer a health benefit. They come in various forms, including supplements, yogurt and other cultured milk foods, and beverages such as kombucha. The original thought was that probiotics could help bolster populations of beneficial bacteria in the gastrointestinal tract while crowding out pathogenic (disease-causing) bacteria, but research now shows that the probiotic bacteria benefit us in more complex and sophisticated modes of action.

Anyone can get probiotics from supplements, foods, and beverages. But do they work? And how should dietitians advise clients and patients? ConsumerLab.com (CL) recently tested 41 popular probiotic supplements and beverages—35 human supplements, three pet supplements, and three beverages—against the following key quality measures:

Number of viable probiotic cells, or colony forming units (CFUs). For products with “live active cultures,” this would mean the organisms are alive. For freeze-dried products, this would mean the organisms can “come alive” from their inactive form. CL tested the products to verify whether they contained the number of CFUs claimed on the label, and that they contained at least 1 billion live organisms per suggested daily adult serving, unless clinical evidence supports a lower dose.
Protection of organisms from the stomach. While some types of bacteria—including most Lactobacillus, Bifidobacterium, and Streptococcus species—can survive stomach acid and make it through to the intestines, others can’t. If a supplement contains bacteria that would be destroyed by stomach acid, it needs to have some form of protection such as an enteric coating or microencapsulation.
Proper disintegration—for products in tablet form—so the organisms can be released in the body. Disintegration tends to not be a concern with capsule supplements.
Lack of contamination. This includes toxic heavy metals (eg, lead, cadmium, and arsenic) and potentially pathogenic bacteria (including E coli and Salmonella) or other microbial contaminants. This is especially important with supplements that have an enteric coating, as the coating would prevent any pathogens in the product from being naturally destroyed by stomach acid.

The Results
Some products were tested specifically for CL’s review, while others already had been tested as part of CL’s Quality Certification Program. All were free from contamination from common pathogenic bacteria and mold and didn’t exceed limits for heavy metal contamination. Of the probiotic supplements for human use, only one, HUM Gut Instinct, didn’t contain the number of CFUs listed on the label. HUM contained 15 billion cells—60% of the 25 billion cells per capsule stated on the label—still a substantial number, but incorrectly labeled, nonetheless. This is an improvement from CL’s 2009–2015 reviews, in which higher percentages of products didn’t contain the amounts of viable cells claimed on the label.

Best in Show
CL chose “top picks” for some of the common and most evidence-based uses of probiotic supplements, including the following:

For preventing antibiotic-associated diarrhea and traveler’s diarrhea, the top picks, from lowest to highest cost, were Culturelle, Nature’s Way Primadophilus Fortify Age 50+ Probiotic, and FloraStor.
For treating constipation in adults, abdominal pain in children, and colic in infants, the winner was Gerber Soothe Probiotic Colic Drops.
For reducing symptoms of irritable bowel syndrome (IBS), the top pick was VSL#3 The Living Shield, which may reduce bloating in diarrhea-predominant IBS.

All three beverages (two kombucha drinks and one probiotic drink) each contained at least 1 billion cells per 8-oz serving. The top pick was GT’s Kombucha Gingerade, a widely distributed brand (in the Seattle area, it’s available not just at Whole Foods and other “health food” stores but also at mainstream supermarkets and Costco). Kombucha is produced by fermenting sweetened black or green tea with bacteria and yeast. GT’s contained 1 billion viable cells and only 25 kcal and 6 g sugar per 8-oz serving (two servings per bottle), which comes from kiwi juice.

Tips for Choosing a Probiotic
According to CL, a properly labeled probiotic supplement will list the types of bacteria and yeast it contains. It should list the amount of viable bacteria/CFU you can expect at the “best by” date. Typically, products contain double that amount at the time of manufacture, as producers expect that one-half will die before the “best by” date, especially if they’re not maintained under ideal conditions. Some products will say something like, “Formulated to contain X billion live bacteria/CFU at time of manufacture and provides an effective level of X billion CFU until at least the ‘best by’ date.”

Unfortunately, some products only listed the number of CFUs present at the time of manufacture, which goes against FDA labeling regulations. However, according to CL, all of the tested products still contained the stated amount despite the “time of manufacture” disclaimer.

Cost isn’t necessarily an indicator of quality. The brands tested for CL’s review ranged from 11 cents to $2.30 for a minimum daily dose, and while higher price tended to be associated with a higher number of CFUs, this wasn’t always the case. The CFUs in the tested products ranged from 100 million to 112.5 billion CFUs per minimum dose, and most products had a daily cost of well under $1.

— Carrie Dennett, MPH, RDN, CD, is the nutrition columnist for The Seattle Times and speaks frequently on nutrition-related topics. She also provides nutrition counseling via the Menu for Change program in Seattle.