What are peptides and how do they work in the body?

Peptides are short chains of amino acids, the building blocks of proteins. They are found throughout your body and serve as signalling molecules, structural components and protectors. Peptide hormones are the best-known category: they direct biological processes by binding to specialised receivers (receptors) on cells, and have been well documented for decades as one of the body's central regulatory systems.

Your body also produces its own peptides that regulate blood vessels. Some narrow or widen blood vessels, while others play a role in ageing processes such as hardening of the arteries and high blood pressure. They are being studied as potential disease markers and as targets for new drugs, but concrete clinical applications do not yet exist.

An important group is the antimicrobial peptides. These short molecules attack bacteria by damaging their outer layer (the membrane), but can also interfere with the cell wall or act inside the bacterial cell. One peptide sometimes uses several attack methods simultaneously. This makes resistance harder to develop, although that risk cannot be entirely ruled out for certain peptides.

Peptides from food are a different story. They are released during digestion or during food preparation. Reviews show that in the laboratory and in animal studies they can lower blood pressure, inhibit oxidative damage and influence cholesterol. Positive signals have also been seen in animal and laboratory research for blood sugar regulation in type 2 diabetes and for bone health. However, clinical evidence in humans is still limited, and safety and efficacy still need to be thoroughly investigated before commercial use.

Finally, peptides are also being studied as a drug-building block: short fragments derived from receptors can switch those receptors on or off, which may open up new treatment possibilities. This is, however, still early-stage research, and the mechanisms are not yet fully understood.