Is it forbidden to eat mayonnaise, shawarma, sausages, and mortadella based on their preparation method or ingredients, and what is the ruling on consuming foods that contain salmonella bacteria?

It is not permissible for a Muslim to harm himself, based on the Almighty's saying: "And do not kill yourselves. Indeed, Allah is to you ever Merciful," and the Prophet's (peace and blessings be upon him) saying: "There should be no harm nor reciprocating harm."

If the harm of a certain food is proven by trustworthy experts, then it is not permissible to consume it. However, if the harm is not proven, or if it is minor or merely a doubtful possibility, then the ruling remains on the principle of permissibility.

There is no objection to eating mayonnaise, shawarma, sausages, and mortadella if they are made from ritually slaughtered meat and if no forbidden ingredients were used in their production, and if the bone of the slaughtered animal is permissible.

Generally, foods are permissible if they are made from pure ingredients, based on the generality of evidence such as the Almighty's saying: "O mankind, eat from what is on earth [that is] lawful and good," and His saying: "It is He who created for you all of that which is on the earth." However, if they are made from forbidden or impure ingredients, they are impermissible.