Gluten-free beer example: Sheehan, Evans & Skerritt, 2001). Brewers who produce low gluten beers are required to test every batch for gluten, and record gluten levels in "parts per million" ('ppm'). Although the barley hordein in such tests may not be detected, smaller pieces of these proteins, known as peptides, may remain and be toxic for celiacs. Those involved in gluten-free brewing, and others representing celiacs or those with other conditions that require a gluten-free diet, tend to be concerned that beer brewed using wheat or barley are not appropriate for those with celiacs or dermatitis herpetiformis, although the carefully controlled gluten
Gluten-free, casein-free diet autism to minimize the buildup of opiate peptides. Reichelt has also published a number of trials and reviews concluding that this diet is effective. The implementation of a GFCF diet involves removing all sources of gluten and casein from a person's diet. Gluten is found in all products containing wheat, rye, and barley. Many gluten-free breads, pastas, and snacks are available commercially. Gluten-free cookbooks have been available for decades. Casein is found in dairy products such as milk, butter or cheese, but is also present in smaller amounts in many substitute dairy products such as vegetarian cheese substitutes and whipped