Do folks with celiac disease really have to worry about enzymes and growth media?

Do folks with celiac disease really have to worry about enzymes and growth media?

Short answer: We don’t know. This is due to the limitations of the assays currently used to detect and measure fermented or hydrolyzed gluten.

Some facts about enzymes:

1. According to the Enzyme Technical Association, “In most cases, enzymes used in food are used as processing aids where they aid in the manufacturing of food or food ingredients but do not have a function in the final food product.”

2. Also according to the ETA, “nearly all commercially prepared foods contain at least one ingredient that has been made with enzymes.” 

3. Unless an enzyme is covered under the Food Allergen Labeling and Consumer Protection Act, processing aids are not required to be included in an ingredients list.

4. Because wheat is a major allergen included under FALCPA, if enzymes are made using wheat or cultivated from microbes grown on wheat containing media, then wheat must be declared on the food label.

5. Barley is not included under FALCPA.

6. If enzymes are made using barley or cultivated from microbes grown on barley, barley does not need to be declared on the food label.

7. Regarding the gluten-free labeling rule, FDA has stated in the Federal Register (see screen shots):

  • “The issue of purity and potential carry-over of growth media containing gluten is a valid concern for both the manufacturers and consumers with celiac disease.”

From Gluten Free Watchdog study Gluten-Free Labeling: Are Growth Media Containing Wheat, Barley, and Rye Falling through the Cracks? J Acad Nutr Diet. 2018;118:2025-2028.

  • Concerning enzymes produced on media containing wheat: “Wheat may be present in any carried-over nutrient media used to grow the microbes.”
  • “The gluten that may possibly be present in the enzyme may be hydrolyzed due to fermentation.”
  • “An important consideration is the amount of potential carryover and how much of the enzyme ingredient is used in the production of the final food product.”
  • The gluten-free labeling rule, “requires some means of demonstrating that the final product has been processed to remove gluten to a level below 20 ppm.”
  • “It is not clear whether the means of measuring compliance with the 2013 gluten-free food labeling final rule for intact gluten would be sufficient to safeguard consumers with celiac disease.”
  • “We decline to exempt enzymes from the rule.”
  • Note: The above applies to barley as well as wheat even thought FDA only mentions wheat.

8. At this time, enzymes used in labeled gluten-free foods must comply with FDA’s rule on labeling of fermented and hydrolyzed foods.

9. At this time, enzymes used in foods labeled gluten-free should not be made using wheat, barley, or rye protein OR cultivated from microbes grown on media containing wheat, barley, or rye protein.

10. Regardless of the above, some products labeled gluten-free also include a Contains wheat statement due to fermentation growth media.

Example: Rainbow Light supplement labeled gluten-free yet includes the statement Contains… wheat traces due to enzyme fermentation media.

11. It is impossible to know if products labeled gluten-free also include barley due to fermentation growth media because barley is not included under FALCPA and does not need to be declared.

12. Some manufacturers voluntarily declare barley in the ingredients list. For example Kame Pad Thai Express Rice Noodles carry a gluten-free claim on product packaging yet barley amylase is declared in the ingredients list. This product may be misbranded as gluten-free.

Thank you to the consumers who provided product photos.


From Federal Register, Food Labeling; Gluten-Free Labeling of Fermented or Hydrolyzed Foods, available at:

Enzyme Technical Association

Enzyme preparations, guidance for industry, available at

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Comments (13)

  • Rosemary McCleod Reply

    I’ve been using Coffee Mate creamer and recently noticed it has maltodextrin as an ingredient, which I believe as a person with celiac I shouldn’t be consuming. Is this correct? It is labeled gluten free but not certified.

    March 23, 2021 at 10:46 pm
    • Celina DeSantis Reply

      Maltodextrin is generally considered gluten-free, even when made from wheat because of the extraction process.

      March 25, 2021 at 2:55 pm
      • Tricia Thompson Reply

        Wheat starch and wheat starch hydrolysates such as maltodextrin are considered ingredients processed to remove gluten by FDA. Wheat starch, glucose syrup from wheat, maltodextrin from wheat, etc. are allowed ingredients in foods labeled gluten-free. The final food product must contain a level of gluten below 20 ppm.

        March 25, 2021 at 3:05 pm
    • Tricia Thompson Reply

      Hi Rosemary, Maltodextrin from wheat (wheat starch actually) is an allowed ingredient in foods labeled gluten-free. If maltodextrin contained protein from wheat this would be declared on the label either in the ingredients list or Contains statement.

      March 25, 2021 at 3:00 pm
      • Rosemary McCleod Reply

        So Maltodextrin in a creamer would be safe for a celiac to consume? Correct??

        March 25, 2021 at 9:02 pm
        • Tricia Thompson Reply

          If wheat is not included in the ingredients list–“maltodextrin (wheat)” or in the Contains list “Contains wheat” then the maltodextrin does NOT contain wheat protein.

          March 26, 2021 at 12:31 pm
  • Angelica Reply

    This is wonderful, thank you. Does this explain why Cheese is almost never certified GF? I’ve suspected the cheese making process for a long time. I can drink milk, but something like cheddar cheese will sicken me every time. It’s either mold allergy or some cross contamination issue. But I’m not sure.

    March 24, 2021 at 2:54 pm
    • Tricia Thompson Reply

      My pleasure, Angelica. While hard cheeses contain enzymes, it would be surprising (to me) if the growth media included barley. If it included wheat (which also would be surprising), it should be declared as required under FALCPA.

      March 25, 2021 at 1:51 pm
    • Melissa Reply

      Angelica, if the cheese that’s making you sick is shredded, sometimes there’s an additive to prevent the cheese from clumping that’s not gluten free.

      March 1, 2022 at 6:35 pm
      • Tricia Thompson Reply

        Just an FYI that additives are covered under FALCPA. This means if an additive contained protein from wheat it would have to be declared in the ingredients list or Contains statement.

        March 2, 2022 at 3:36 pm
  • Rosemary McCleod Reply

    Thank you that clears things up.

    March 26, 2021 at 5:14 pm
  • Kate Delisle Reply

    I just opened a package of “Armstrong Combos”, and on the ingredient list of the hard cheese sticks, it includes “Bacterial culture (barley). So is this unsafe for coeliacs?

    April 29, 2024 at 12:50 pm
    • Tricia Thompson Reply

      Hi Kate, This appears to be a Canadian product. In Canada barley protein must be declared. Is this product labeled gluten-free?

      April 29, 2024 at 2:36 pm

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