How to Read Probiotic Food Labels: A Step-by-Step Guide

What to Look For on a Label: Live Cultures, Strains, and CFUs

When you pick up a food product that claims to contain probiotics, the label should tell you three basic things: that live cultures are present, which specific strains they are, and how many of them are guaranteed at the end of the product's shelf life. In practice, food labels vary widely, so it helps to understand what each piece means.

Experts recommend that a meaningful probiotic label includes the genus, species, and strain designation for each strain, as well as the minimum viable number of each strain expressed in colony-forming units (CFU). This guidance comes from the 2002 FAO/WHO working group and remains a useful benchmark for evaluating products.

Sources: International Scientific Association for Probiotics and Prebiotics (ISAPP)

Step 1: Check for Live Cultures or a Probiotic Claim

Some products are labeled “probiotic,” while others say “live cultures” or “active cultures.” The word “probiotic” is not officially defined in US food labeling regulations, and the FDA does not require foods to declare probiotic content. So a label that says “probiotic” is a marketing claim, not a regulated term.

If a product is a dietary supplement containing live microbes, the FDA treats those microbes as dietary ingredients. For marketing and advertising, the FTC requires that claims be truthful and not misleading, with adequate substantiation. While this applies to advertising rather than the label itself, it is a useful benchmark for evaluating the overall presentation.

• Look for terms like ‘live cultures,’ ‘active cultures,’ or ‘probiotic’ on the package.
• Remember that a food can contain live cultures but not be labeled as a probiotic, and vice versa.

1. Look for a phrase such as “live cultures,” “active cultures,” or “probiotic” on the package.
2. If the product is a dietary supplement, note that the FDA considers live microbes to be dietary ingredients.
3. Remember that the term “probiotic” is not defined in US food labeling rules, so treat it as a marketing claim.
4. Keep in mind that FTC rules require marketing claims to be truthful and substantiated.

Sources: U.S. Food and Drug Administration (FDA), Federal Trade Commission (FTC)

Step 2: Identify the Specific Probiotic Strains Listed

A proper probiotic label identifies each strain by its genus, species, and strain designation, such as Lactobacillus rhamnosus GG. Some food labels list only the genus and species, or only a broad group like ‘bifidobacteria’ or ‘lactobacilli.’ The FAO/WHO guidance says the label should include the full strain designation, but many fermented foods do not meet that ideal.

Consider whether the product provides health benefits documented for those specific strains. Products that contain undefined microbial content and lack studies showing health effects may not meet the scientific criteria for a probiotic, even if the label suggests otherwise.

• Find the full scientific name, including the strain code if present.
• If the label only says ‘lactobacilli’ or ‘bifidobacteria,’ treat the product as a source of live cultures rather than a well-defined probiotic.

Sources: International Scientific Association for Probiotics and Prebiotics (ISAPP)

Step 3: Look for the Concentration (CFUs or Colony-Forming Units)

The label should state the number of viable cells, typically as colony-forming units (CFUs). For single-strain products, a total CFU count can be meaningful. For multi-strain products, a total CFU only tells you the sum, not how many of each strain are present. The FAO/WHO guidance asks for the minimum viable numbers of each strain at the end of shelf life, but many labels fall short.

One important warning: a label that says “CFU at time of manufacture” is not as useful, because the count may decline during storage and shipping. You want a count that is guaranteed at the end of the product's shelf life, not just when it was made.

• Look for the total CFU, and for multi-strain products, ideally the CFU for each strain.
• Prefer labels that guarantee CFU through the end of shelf life over those that state counts at time of manufacture.

Sources: International Scientific Association for Probiotics and Prebiotics (ISAPP)

Step 4: Verify the Product's Handling and Storage Instructions

Live microbes are sensitive to heat and moisture. The label should tell you how to store the product to keep the cultures alive—such as “keep refrigerated” or “store in a cool, dry place.” Follow these instructions, because the CFU count at the end of shelf life depends on proper handling.

Also note that pasteurization kills live microbes. If a product was pasteurized after cultures were added, it cannot contain live probiotics unless they are added afterward. The label should indicate whether the product is pasteurized, and you can look for terms like “after pasteurization” if cultures are added later.

• Read storage instructions and follow them.
• Ask whether the product was pasteurized after culturing; if so, it likely contains no live probiotics.

Sources: International Scientific Association for Probiotics and Prebiotics (ISAPP), U.S. Food and Drug Administration (FDA)

Common Misleading Terms on Packaging and How to Interpret Them

Some product labels use words that sound scientific but do not guarantee live probiotics. Here is how to interpret common vague terms:

• 'With probiotics' — This claim does not mean the product contains a meaningful number of live cultures. Check for a CFU count and strain names.
• 'Contains bifidobacteria' or 'with lactobacilli' — These broad terms may refer to ingredients added before processing or in unknown amounts. Look for the full strain name.
• 'Live cultures' — This usually indicates the product is not pasteurized after culturing, but it does not tell you the species, strains, or quantities.
• 'Probiotic' on a pasteurized product — If the product was heat-treated after cultures were added, interpret this claim with caution; the live microbes may be gone.
• Always cross-check the marketing terms against the ingredient list and nutrition facts for processing clues.

Sources: International Scientific Association for Probiotics and Prebiotics (ISAPP), Federal Trade Commission (FTC)

Label-Reading Checklist and Quick Reference Table

Use this checklist when evaluating any food product that claims to contain probiotics. Keep in mind that the table below summarizes the key information to seek and what it means.

• Does the label say ‘live’ or ‘active cultures’?
• Are specific strains listed by genus, species, and strain designation?
• Is there a guaranteed CFU count at the end of shelf life?
• Are storage instructions clear?
• Was the product pasteurized after culturing?
• Does the label make health claims that seem too broad? Check for substantiation.

Sources: International Scientific Association for Probiotics and Prebiotics (ISAPP)

Examples of Label Reading for Common Probiotic Foods

Yogurt often lists “live and active cultures” on the container. For a typical yogurt label, you might see a statement like ‘Contains live and active cultures including Lactobacillus bulgaricus and Streptococcus thermophilus.’ If the label does not give a CFU count or full strain names, it is still a fermented food with live microbes, but you cannot match it to specific research.

Kefir usually contains a broader mix of bacteria and yeasts. A common kefir label might say ‘Contains live kefir cultures’ without specifying strains. Look for additional details such as ‘Lactobacillus kefiri’ or a CFU count if you want a more defined product.

Plant-based yogurts and fermented drinks also claim probiotics. For example, a coconut yogurt label may say ‘with live cultures’ but then list ‘contains probiotics’ in smaller text. Check whether the product was pasteurized after culturing by looking for terms like ‘after pasteurization’ or the presence of ‘live cultures’ near the ingredient list to interpret the claim correctly.

Sources: International Scientific Association for Probiotics and Prebiotics (ISAPP)