Evidence check: Zink in the context of gut health

Zinc is essential for gut health, particularly for immune function of the intestinal mucosa, maintaining barrier integrity, and modulating the microbiome. Human studies show that zinc supplementation can reduce the duration and severity of diarrhea, especially in children. There is also moderate evidence for benefits in inflammatory bowel disease (IBD). Zinc deficiency impairs gut barrier function and promotes inflammation. However, supplementation without confirmed deficiency is not generally recommended, as high doses can cause copper deficiency and gastrointestinal upset. Genetic tests for zinc status are not reliable; blood tests (serum/plasma zinc) are preferred. The evidence for zinc in general gut health is human-moderate – clear benefits exist in deficiency states, but extrapolation to healthy individuals is limited.