Classification and biochemical category: the tTG/DGP fusion peptide is a synthetic peptide antigen used in serologic assays. It presents linked epitopes from tissue transglutaminase and deamidated gliadin, creating a composite target for antibody binding. Discovery and clinical relevance: separate antibody responses to tTG and to deamidated gliadin peptides have been identified as markers of immune reactivity to gluten-related peptides. Fusion peptides were developed to capture antibodies that recognize the combined neo-epitope formed when transglutaminase modifies gliadin, improving assay sensitivity for those specific immune patterns. Core function: the fusion peptide itself is not a native human protein but serves as a probe to detect circulating IgA and IgG that bind to transglutaminase-associated gliadin epitopes. Detection reflects immune recognition of modified gluten peptides at the mucosal or systemic level, depending on isotype patterns.

Elevated antibody binding to the tTG/DGP fusion peptide suggests stronger immune recognition of transglutaminase‑modified gliadin epitopes. If the response is predominantly IgA, that pattern points toward mucosal immune activity; if IgG is higher, that suggests a more systemic antibody response. Low or absent binding indicates limited immune recognition of those specific modified peptides. Interpretation should rely on the full Food Zoomer panel and clinical context: single-marker results are one piece of a broader pattern that includes other gluten-family markers, isotype distribution, symptom history, and additional lab findings.

Food Zoomer includes the tTG/DGP fusion peptide to capture peptide-level immune responses linked to transglutaminase‑modified gluten fragments. This marker helps distinguish whether immune activity clusters around gluten‑related neo-epitopes and adds clarity to IgA versus IgG patterns, supporting more precise dietary and testing strategies based on individual immune profiles.