The correct answer to this question is germs. You will understand this question when you first get the meaning of antigen. The term antigen refers to any foreign substance that induces an immune response when it enters into an animal or human body.
Germs are pathogenic organisms, meaning they are not antigens. In other words, they are non-antigens. Although germs can cause diseases in the human body, they are never antigens. However, the toxins they produce when they enter into the human body are antigens. The reason why germs are considered non-antigens is that they are microorganisms, and they cause diseases in living things.
The term antigen only describes any foreign material that causes the immune system of the body to produce antibodies. The body needs to produce antibodies in order to fight the antigen. Antigens can be non-living substances as well as substances in living cells.
When you say non-antigen, you mean to say that this will not contain the properties of antigen materials. This means that it will not have the ability to bind to an antibody or another antibody receptor. Antigens will attach to some healthy cells and cause havoc to the rest of the body.
They are meant to help induce an immune response so that the body will know that it is trying to fight something foreign that has entered the body. There are not enough details that will provide answers to what some examples of non-antigens are.
An antigen is something that illicitness an immune response. Gut flora, for example, is a non-antigen. It does not create an immune response from your body, and it is a bacterium. Gut flora is the microorganisms including bacteria, archaea, and fungi that reside in the digestive tracts of humans and other animals, including insects.
The opposite of an antigen could be a protein produced by B-lymphocytes that binds to a specific antigen. It could be a cell or group of cells that receive stimuli. An antigen is any material that is foreign to the body that involves an immune response either alone or after creating a complex with a larger molecule capable of binding with a product. Germs and toxins of germs are also non-antigens.