A drug that breaks down gluten into harmless smaller molecules has shown success in randomized human trials, but even the company that makes it is concerned about exaggerated reports of how widely it can be used.
The drug, GluteGuard, is already on the market, but only as a “complementary medicine”, a category that means it does not require evidence that it actually works. Moreover, GluteGuard cannot replace a gluten-free diet for celiacs, for many of whom consumption of gluten can be life-threatening. Nevertheless, GluteGuard's makers, Glutagen, claim that it can ease the discomfort of those with milder reactions to the protein. Further trials are underway to find out how effective it might be, and whether it could be used as a back-up after accidental gluten consumption.
GluteGuard is based on the enzyme caricain, produced by the papaya plant. According to retired professor Hugh Cornell, caricain not only reduces gluten to smaller molecules, but further breaks down those products that negatively impact individuals affected by gluten.
Unfortunately, caricain is destroyed by the acidic environment of the stomach, so GluteGuard uses an enteric coat that resists acids, while breaking open in the alkaline conditions experienced in the small intestine, allowing the caricain to do its work.
The ideal anti-gluten treatment would be so effective that it would allow celiacs to eat a normal diet. Cornell doesn't expect GluteGuard to meet that standard. However, Cornell told IFLScience that even people who choose gluten-free foods often get exposed to small amounts of gluten through cross-contamination, and a drug that minimized the effects could help their bodies recover.
Cornell has published a double-blind study in the International Journal of Celiac Disease, where 14 celiacs were given GluteGuard, while six others took a placebo daily. Both groups ate a diet containing 1 gram (0.035 ounces) of gluten a day. (A single slice of whole wheat bread has almost five times as much).
Two-thirds of those taking the placebo experienced symptoms so painful they dropped out of the program, while only one of those on GluteGuard did likewise. A previous study on people with dermatitis herpetiformis, skin ulcers induced by exposure to gluten, saw a similar dropout rate among those on the placebo, while most given the GluteGuard experienced relatively mild symptoms.
Despite the small size of the studies, Cornell notes the studies demonstrate GluteGuard makes a difference, but does not want to encourage celiacs to think the drug he devised can replace a careful diet.
Potentially, a much larger market for GluteGuard exists among people with what has been called non-celiac gluten sensitivity (NCGS). Debate rages over whether NCGS even exists, or if people with sensitivity to wheat or short-chain carbohydrates are being misdiagnosed. Cornell told IFLScience he believes NCGS is real and affects people whose bodies can break down some gluten, but lack the capacity to deal with the quantities encountered in a typical diet.
For those whose NCGS causes discomfort, rather than damage, on encounters with gluten, it might be safe to use GluteGuard as a substitute for a low-gluten diet if they find standard bread loaves or pasta plates too tempting. Nevertheless, Glutagen notes that even many people with NCGS apparently experience severe consequences, and should use GluteGuard as an adjunct, rather than repalcement for, a gluten-free diet. Celiacs are estimated to make up 1 percent of the population, while claims for NCGS go as high as 10 percent, suggesting a much larger pool of potential beneficiaries, if used with care.