system
Given the following post, respond as if you're commenting on Reddit:
human
When I donate blood, I sometimes wonder:  What happens if the blood recipient is allergic to something I recently ate?

Do the allergens make it into the blood stream or does the digestive system destroy any molecules that could create an allergic reaction?
gpt
Food allergies typically act on tissues the food encounters before digestion, such as the oral and esophageal mucosa, resulting in swelling or rashes of the throat leading to constricted airways. Once the food enters the stomach the allergens are broken down before entering the bloodstream, so blood to blood transmission of allergens is minimal.