Non-celiac gluten sensitivity not yet universally adopted. For people on a gluten-free diet who are unable to perform an oral gluten challenge, an alternative to identify possible celiac disease is an in vitro gliadin challenge of small bowel biopsies; this test is only available at selected specialized tertiary-care centers. After exclusion of celiac disease and wheat allergy, the subsequent step for diagnosis and treatment of NCGS is to start a strict gluten-free diet (GFD) to assess if symptoms improve or resolve completely. This may occur within days to weeks of starting a GFD, but improvement may also be due to a non-specific, placebo
Wheat gluten (food) 蛋 (tan, from 蛋白 (tanpaku, "protein")). The meaning of the word "seitan" has undergone a gradual evolution. The initial product, imported from Japan in 1969 was a very salty seasoning, the color of soy sauce, sold in a small glass jar or plastic pouch, to be used as a seasoning for brown rice. The name gradually came to refer to any wheat gluten seasoned with soy sauce. The people most responsible for this change are Nik and Joanne Amartseff, who invented Tan Pups in 1972 and John Weissman, who in 1974 invented Wheatmeat (first meatballs then cutlets made of seitan)