“How can I protect my child from the development of celiac disease?” Parents and parents-to-be frequently ask this question when a family member has this condition. Until now, many clinicians have recommended the administration of small amounts of gluten during the “window of opportunity” — at 4 to 6 months of age — preferably while maintaining breast-feeding. This advice was based on experience from the Swedish celiac disease epidemic, in which a large increase in the prevalence of the disease among infants was attributed to earlier introduction of gluten,1 as well as on U.S. data indicating that the introduction of . . .