If you eat bread and peanut together and you are allergic to peanut but you are not allergic to bread, will you become allergic to bread since the bread will be mixed in with peanuts in your digestive system?

No: Allergic reaction is very specific and there is very little evidence that mixing foods induces new allergens although it is theoretically possible.

Food allergy: If you have not seen an allergist please see one. You need to find out if you have allergies to other foods. Eating PB and bread together does not make your allergic to bread. Peace and good health.