Is a small amount of gluten harmful?

You may be the most gluten-conscious person in the world, but there's still a chance that gluten will enter your gluten-free child's diet. Not to worry. Gluten is not poison. It may temporarily cause some discomfort, or diarrhea.

The intestine is a forgiving organ. It has some of the most rapidly growing tissues in the body, and is constantly repairing itself. So minimal, infrequent exposure is unlikely to cause any long-term problems, although it may cause short-term symptoms.

On the other hand, repeated exposure does have the potential to cause more severe symptoms and consequences for children with celiac disease and non celiac gluten sensitivity. 

In essence, some people are more sensitive to gluten than others. Understand that even gluten-free products can have tiny amounts of gluten (up to about 10 mg per pound of bread, for example). Since researchers estimate that it takes about 10 mg to do any intestinal damage, your child would have to eat an entire pound of that bread to notice any symptoms.  On the other hand, regular bread contains much larger amounts and a single slice might cause symptoms that last for several days. 

Do try to be thoughtful in how you present this to your children and others. I recall a parent telling me she had tried to steer her son away from gluten by telling him that it was poison. That backfired when she took her son into the grocery and he was screaming in the bread and cereal aisles because of all the poison surrounding him.