Human Defensin 5 (HD5)

Human Defensin 5 (HD5) is a small protein produced mainly in the small intestine, part of the immune system’s first line of defense. It has antimicrobial properties, meaning it can kill or inhibit bacteria, fungi, and viruses that might cause infections. HD5 helps maintain the balance of good bacteria and protect the gut from harmful pathogens. It is part of the body’s innate immunity, acting quickly at mucosal surfaces to keep them healthy and prevent illness.