Labdoor analyzed 30 best-selling probiotic supplements in the United States, measuring amounts of total anaerobic bacteria, genera-specific bacteria, and potential contaminants (mold, yeast, and pathogenic bacteria, including E. coli O157:H7, Salmonella spp., and Staphylococcus aureus).
The tested products recorded large label claim variances, averaging viable bacteria measured at 206% off their stated label claims. 21 of 30 products recorded total viable bacteria at least 50% off their label claims, 7 products measured probiotic bacteria at least 100% off their claims, and 2 products exceeded a 1000% label claim variance.
Two probiotic supplements recorded measurable amounts of contaminating yeast residues. Typically, probiotics will test positively for yeast if they contain beneficial yeasts (i.e. Saccharomyces bouldarii); these products did not claim any yeast probiotics in their formulations. Labdoor scientists also identified two products containing caramel color and propyl gallate, controversial additives linked to cancer in animal testing.
The tested products recorded large label claim variances, averaging viable bacteria (calculated as the sum of viable organisms belonging to claimed genera) at 206% off their stated label claims. 21 of 30 products recorded total viable bacteria at least 50% off their label claims, 7 products exceeded a 100% label claim variance, and 2 products exceeded a 1000% label claim variance.
Sedona Labs iFlora was the top-ranked product based on label accuracy, exceeding its label claim by 13%. Equate Probiotic was the category’s worst performer, recording 2400% more bacteria than claimed on its Supplement Facts label.
28 of 30 products passed all purity tests, indicating absence of contaminating yeast and mold residues and harmful bacteria, including the pathogenic strain of E. coli (E. coli O157:H7), Salmonella spp., and Staphylococcus aureus.
4 of 30 products recorded at least 5 calories per serving, with the majority of calories coming from sugar content. Schiff Digestive Advantage Probiotic Gummies recorded 2 grams of sugar per serving and 10 calories, the highest sugar content/serving in this category. Rainbow Light Probiolicious Gummies recorded 16 calories per serving, with most of the calories expected to come from prebiotics (carbohydrates including inulin and fructooligosaccharides) and sugar alcohols (xylitol).
Probiotics are generally considered safe for most people, but may cause gastrointestinal discomfort (abdominal tenderness, pain, gas, and/or diarrhea) if intake exceeds individual needs.
While there are no established Upper Limits for probiotics, various clinical studies have noted that doses up to 15 billion CFUs of beneficial bacteria have shown efficacy in the maintenance of digestive health/reversing occasional irregularities and doses up to 450 billion CFUs have shown efficacy in the treatment or symptomatic relief of Irritable Bowel Syndrome (IBS).
There are currently no established Daily Values or Recommended Dietary Allowances set for probiotic intake. Generally, more severe conditions require higher dosages and, often, particular probiotic strains that have shown efficacy against specific indications.
Various clinical trials have indicated that doses ranging from 1 to 15 billion CFUs of probiotic bacteria (as one or a combination of different genera/species) have shown efficacy in the maintenance of digestive health and/or reversing occasional irregularity. Species of the genus Lactobacillus (L. rhamnosus GG, L. casei, and L. acidophilus) and Bifodobacterium (B. lactis) have been shown to be particularly effective for this use-case.
Clinical study has also indicated that doses ranging from 6 to 450 billion CFUs of probiotic bacteria have shown efficacy in the treatment or symptomatic relief of Irritable Bowel Syndrome (IBS), a more severe gastrointestinal condition characterized by abdominal cramps, pain, diarrhea, and constipation. Species of Lactobacillus (L. salivarius, L rhamnosus GG), Bifidobacterium (B. infantis, B. animalis), as well as Saccharomyces bouldarii have shown efficacy against IBS.
9 of 30 products recorded total viable bacteria counts below 1 billion CFUs. Schiff Digestive Advantage Probiotic Gummies consisted of just one species (B. coagulans) and recorded the fewest viable bacteria, measuring at just 2.8 million CFUs per serving.
Note: Probiotic supplements may report amounts of viable bacteria as number of organisms or as Colony Forming Units (CFUs). It should be noted that a CFU may represent one or more cells, depending on the probiotic being evaluated. For example, if a particular strain will form a colony from a minimum of 3 chained cells, then the number of viable bacterial cells would total 3x the CFU count.
Furthermore, our testing included enumeration of both total anaerobic bacteria and genera-specific bacteria, with the expectation that both analyses would result in similar amounts. In fact, significant differences existed between the two analyses, with anaerobic counts often totaling less than the sum of all claimed genera. Possible reasons include:
If a bacterial species can grow both aerobically and anaerobically, anaerobic testing would not fully recover all viable bacteria of that species. In fact, both Lactobacillus and Bifidobacterium are facultative anaerobes, or bacteria with the ability to grow with and without access to oxygen.
Use of culture media impacts overall viability, as more selective media used in genus enumeration (which caters to the nutritional requirements of the organism) may lead to higher recovery than using a less selective culture media for total anaerobic enumeration.
Labdoor’s analysis is based on organizational standards and reports all cell counts in CFUs. To account for the discrepancies in enumeration, only the sums of viable bacteria belonging to all claimed genera were used to generate Labdoor’s rankings.