CLEC7A

In one line: A sensor on immune cells that "trains" your defences when it detects certain sugars.

CLEC7A (Dectin-1) is a sensor sitting on your front-line immune cells. It recognises beta-glucans — special sugars found in mushrooms and yeast — and when it does, it primes the immune system to respond faster and stronger to threats. Scientists call this "trained immunity."

This is why beta-glucan and medicinal-mushroom supplements can reduce how often you catch colds — they gently rehearse your immune defences so they're quicker off the mark when a real infection shows up.

Think of it as a fire drill for your immune system.