My April 2017 post was an article on Finding a High Quality Probiotic. This focused on dietary supplement products. What about probiotic foods? They can be less clear than supplements for consumers to understand. Probiotic foods are often labeled with little information about the probiotic content, especially with regard to strains, levels of live probiotics and health benefits.
Due to limitations imposed on food labeling by regulatory frameworks, companies may not be able to communicate about some human studies that have been conducted on that product. If you are looking for a probiotic for a specific health benefit, useful guides for this are Clinical Guide in USA and World Gastroenterology Organisation’s Practice Guideline on Probiotics and Prebiotics.
With regard to the strains contained in probiotic foods, unfortunately, some foods only state ‘probiotic’ or the genus and species – they don’t include strain designations. This makes it impossible for consumers to link the food with specific, tested benefits.
Even more often lacking from probiotic food labels is a statement of the level of probiotic contained in the product. The product website will sometime provide this information. But sometimes it does not, and this leaves the consumer unsure if an effective level of probiotic is contained in the product. In the case of foods, you may see probiotic bacteria listed on the label (e.g., “contains Lactobacillus acidophilus and Bifidobacterium lactis”), but this does not guarantee that they are present at a ‘probiotic’ dose.
When choosing a probiotic food over a supplement, you must be sure that the food fits into your healthy diet. Flavored yogurts contain milk and fruit, which contain natural sugars, but also may be further sweetened. Some flavored yogurts can contain 10 or more grams of added sugar per serving. The American Heart Association suggests limiting added sugar to 37.5 grams/day for men or 25 grams/day for women. The presence of added sugar in these products does not ‘cancel out’ the probiotic benefit. Many of the studies looking at health benefits of probiotic yogurts have been done with sweetened products.
Consumers may find helpful suggestions developed by the International Scientific Association for Probiotics and Prebiotics. This page offers “Probiotics: A Consumer Guide for Making Smart Choices”, an infographic on probiotics, and other useful information.
Canadian probiotic foods
For those of you interested in a scientific report about Canadian probiotic foods – that I believe unfairly characterizes probiotic foods – keep reading.
Scourboutakos and colleagues screened food product labels in Canada for all products labeled ‘probiotic’. They recorded all claims, species, strain(s), and dosage for the identified probiotic foods. The Canadian regulatory framework allows foods to display a general probiotic health claim (e.g., supports digestive health) if the label correctly identifies the presence of one or more recognized probiotic species and if the dose is at least 109 cfu/serving.
They then conducted a systematic review of human trials for the strains contained in the food products. They did not include any human studies that were not done in a similar food format as the probiotic product.
Their overall goal was to determine if there was a match between the dose of probiotic delivered in the food and the dose used in human studies. They found that in many cases, published human studies used doses that exceeded the levels delivered in the food products. This led them to conclude that “…probiotic dosages … are currently too low to provide the benefits shown in clinical trials.”
Although this may be a true statement, it is misleading. It is not reasonable to expect that a probiotic food deliver any and all established benefits. Some benefits may require higher doses than present in a particular food, but that does not mean that the probiotic food doesn’t deliver some benefit. And if the product does not claim the benefit associated with the higher dose, then it is unfair to suggest the food is somehow misrepresented or inferior.
The misleading nature of this paper’s conclusions did not prevent a news story, which portrayed probiotic foods in a negative light.
This particular story concluded with another misstatement, “Fermented foods, such as sauerkraut and kimchi, are also sources of probiotics.” Fermented foods are sources of live bacteria, but most are not sources of probiotics. Probiotics must be studied in controlled human trials and be shown to provide a health benefit. Most fermented foods have not been researched in this fashion. See here for correct information on fermented foods.
Mismatch between Probiotic Benefits in Trials versus Food Products. Scourboutakos MJ, Franco-Arellano B, Murphy SA, Norsen S, Comelli EM, L’Abbé MR. Nutrients. 2017 Apr 19;9(4).