The average gluten-containing diet contains roughly 10-40 grams of gluten per day. This figure is based on the amounts of gluten in your average slice of whole wheat bread, which contains around 4.8 grams of gluten (10% gluten by weight), and the amount of gluten in a serving of pasta, which is roughly 6.4 grams of gluten (11% gluten by weight). The smallest amount of gluten which has been shown by a biopsy to cause damage to a celiac is 0.1 gram per day (Catassi et al.). This is approximately the amount of gluten contained in 1/48th of a slice of bread! The biopsies in this study showed an increase in intraepithelial lymphocyte count, one of the earliest signs of damage. The challenge was on 10 patients (children) for 28 days each. Four of the patients showed an increase in IgA antigliadin antibodies. The intestinal permeability test remained normal.