Evidence check: Transferrin in the context of gut health

Transferrin is an iron-transport protein primarily used to assess iron status (deficiency or overload). In the context of gut health, transferrin can be indirectly relevant: In inflammatory bowel disease (IBD) or celiac disease, iron deficiency anemia may occur, reflected by elevated transferrin levels and low transferrin saturation. Conversely, in hemochromatosis (iron overload), transferrin saturation is elevated – a condition that may also affect gut barrier function. However, transferrin is not a specific gut health marker; direct studies linking transferrin to gut health are lacking. The evidence for transferrin as a gut health biomarker is therefore indirect, based on observational studies of iron metabolism. Caveat: Transferrin levels are influenced by inflammation, liver function, and hormones (e.g., oral contraceptives). An isolated transferrin test without other iron parameters (ferritin, serum iron, hemoglobin) is of limited value. For a comprehensive gut health assessment, more specific markers like calprotectin or zonulin are preferable.