Gluten Content of Gluten Digestive Enzyme Supplements: A Very Brief SummaryTricia Thompson
This is not a commentary about whether individuals with gluten-related disorders should use gluten digestive aids or whether there is any benefit to these supplements. For an excellent article on enzymes and current medical thinking, please see the interview conducted by NFCA available HERE.
As many of you know Gluten Free Watchdog has been sending various “glutenase” enzyme supplements to the lab for gluten testing. Initial results were very troublesome. But based on additional testing following a modified testing protocol, the products appear to contain levels of gluten below the lower limit of quantification.
The information provided below may be a bit technical. My apologies.
Background: in May 2015 an enzyme-industry insider working for a manufacturer who supplies enzymes to industry for use in supplements contacted Gluten Free Watchdog. He was concerned because one of the enzyme ingredients widely used in “glutenase” enzyme supplements (supplements marketed to help break down gluten) was testing very high for gluten (> 270 ppm) using the competitive R5 ELISA (the assay used to detect hydrolyzed gluten).
Note: According to the individuals I have communicated with in the enzyme industry, enzymes used in glutenase supplements are generally derived from bacteria grown on wheat or barley. This is necessary to generate the enzymes that are used in these supplements to supposedly hydrolyze gluten.
What GFWD Tested
Three popular glutenase enzyme supplements were purchased for testing. GFWD asked the lab—Bia Diagnostics–to test the enzymes following the same protocol used by the enzyme supplier who contacted GFWD (i.e., product tested using both the sandwich and competitive R5 ELISAs; no modifications made).
Initial testing was alarming, especially for two of the supplements. Extraction values for one supplement ranged from 24 ppm to 138 ppm gluten using the competitive R5 ELISA. However, the lab used by Gluten Free Watchdog–Bia Diagnostics–questioned the findings. They felt that the results were false positives caused by the enzymes reacting with the assay. To determine if this was the case, the enzymes were deactivated via boiling and the product was retested. Results of the retest were below the lower limit of quantification of 10 ppm gluten.
Gluten Free Watchdog contacted the manufacturer of both enzyme products that tested high for gluten during the first round of testing. Manufacturer testing initially found high levels of gluten for both products using the competitive R5 ELISA (> 270 ppm and 187 ppm). The manufacturer then deactivated the enzymes and the analysis was rerun. Results of follow-up testing were below the limit of detection.
The manufacturer writes, “Our dietary supplements contain a unique enzyme matrix, which includes various proteolytic enzymes. These proteases degrade the protein bonded to the ELISA test wells which creates interference with the assay thus creating a false positive. In order to correctly analyze these products, protease enzymes must be completely deactivated to prevent interfering with this analysis. Because some proteases are stable at higher temperatures, samples are subject to boiling, plus washing with a protease inhibitor cocktail to ensure deactivation.”
Samples were also sent to a noncommercial lab for testing via mass spec. Results indicate no detectible gluten in the enzymes tested. However, testing enzymes via mass spec proved to be difficult and according to the lab more work is needed to determine how best to test enzymes using mass spec.
The “glutenase” enzyme supplements tested by Gluten Free Watchdog do not appear to be contaminated with residual gluten. It is important to note that when enzyme supplements are tested for gluten, the enzymes must be deactivated to prevent false positives.
© Copyright August, 17 2015 by Tricia Thompson, MS, RD for Gluten Free Watchdog. All Rights Reserved.