Myths vs facts: Transferrin and gut health

Transferrin is an iron-transport protein primarily produced in the liver and not directly linked to gut health. A common myth suggests that elevated transferrin levels indicate a compromised gut barrier or intestinal inflammation. In reality, transferrin is mainly used to assess iron status, such as in iron deficiency or overload. Gut health is better evaluated through markers like calprotectin, zonulin, or lactulose/mannitol tests. An indirect connection exists via iron absorption: chronic gut inflammation (e.g., Crohn's disease) can cause iron deficiency, which then lowers transferrin saturation. However, transferrin itself is not a specific gut marker. The evidence for a direct link is weak and based on mechanistic reasoning rather than clinical trials. Consumers should not rely on transferrin alone to judge gut health.