Immunoglobulin A (IgA) is an antibody and, in its secretory form, is the main immunoglobulin found in mucous secretions, including tears, saliva, colostrum, intestinal juice, vaginal fluid and secretions from the prostate and respiratory epithelium. It is also found in small amounts in blood. Because it is resistant to degradation by enzymes, secretory IgA can survive in harsh environments such as the digestive and respiratory tracts, to provide protection against microbes that multiply in body secretions.
There are at least three main types of antibodies associated with food sensitivities - IgE, IgA, IgG. Ig stands for Immunoglobulin, and these are proteins produced by the body to deal with foreign pathogens. They are specific to the pathogen. So what we're talking about here is when an antibody is produced to something that should be benign, like a food.
Gluten intolerance linked to IgA (Attackers) causes damage to the intestinal lining, allowing partially digested food to pass into the body. This is often known as leaky gut syndrome.