In addition, the researchers found that the contents of serum globulin and lysozyme, globulin ratio, the activity of superoxide dismutase, and the antibody titer were significantly higher in the immunized group than those in the control group.

Source: https://phys.org/news/2023-02-significant-intestinal-symbiotic-microbiota-metabolism.html

Superoxide dismutase (a powerful antioxidant enzyme that neutralises potentially damaging free radicals) requires zinc for its action.

Source: https://www.mirror.co.uk/news/health/most-lack-least-eight-key-30297197