Antibodies are used as biomarkers to assist in distinguishing gluten immune reactivity and sensitivity, silent celiac disease, Crohn's disease and other gut-related pathologies from classical celiac disease. In one class of embodiments, sera, saliva or other samples from a human or other animal are tested for antibodies to (a) a wheat antigen; (b) a gliadin antigen; and (c) one or more of a wheat germ agglutinin, a gluteomorphin, a glutenin, a deamidated glutenin, a prodynorphin, and a dynorphin. Test results are considered particularly interesting where the wheat antigen and the gliadin antigen are both selected from the group consisting of native and deamidated forms of α-gliadin 33-mer, α-gliadin-17-mer, γ-gliadin-15-mer, ω-gliadin-17-mer, and glutenin 21-mer. Test plates and kits can advantageously test for antibodies to at least three, five, seven or all of mixed wheat antigens, α-gliadin, γ-gliadin, ω-gliadin, glutenin, α-glutenin, wheat germ agglutinin, gluteomorphin, prodynorphins, transglutaminase-2, transglutaminase-3, transglutaminase-6, and gliadin-bound transglutaminase.