We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.
Health

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What is Lactoferrin?

By Helga George
Updated: Jan 22, 2024

Lactoferrin (LF) is a human protein that has many functions. Also known as lactotransferrin, it is found in breast milk and in mucosal secretions, such as saliva, tears, and gastric secretions. This protein has strong antibacterial activity, due to both iron-binding properties and the intrinsic structure of the protein. It also modulates inflammatory events. In combination with hypothiocyanate, lactoferrin is used to treat cystic fibrosis patients.

The antimicrobial defense system of the respiratory tract involves layers of defense mechanisms that protect it, and the lungs, against microorganisms that have been inhaled. Lactoferrin is an essential part of this system. It can be broken down, by protease activity, into smaller fragments to produce two small peptides known as lactoferricin and kaliocin-1, both of which have antimicrobial activity.

Lactoferrin is an iron-binding protein, but unlike most proteins that bind iron, it does not contain a heme group. For this reason, the protein is in the category of non-heme iron-binding proteins. The ability to bind iron causes it to have inhibitory properties toward a range of gram-positive and gram-negative bacteria, and some fungi. These organisms need iron for growth, but cannot utilize it if has been sequestered by lactoferrin. The ability to stop the growth of the microorganisms without killing them is known as being bacteriostatic.

In some cases, gram-negative bacteria produce molecules that sequester iron, and secrete them into the environment to bind up all the iron. This can thwart the bacteriostatic properties of lactoferrin. It appears that part of the protein structure itself is antibacterial, however, even in the absence of iron. This combination of factors accounts for the potent antibacterial activities of this molecule.

Lactoferrin is the second most common protein in human breast milk. It is most abundant in milk produced in the days immediately following birth, and appears to supply newborn infants with the iron they need to thrive. This protein is also present in cow’s milk, but at much lower levels than in human milk.

This molecule is also involved in fighting inflammation. It is stored in the granules of neutrophils — the most common variety of white blood cells in humans. These cells respond quickly to sites of inflammation or bacterial infection, and secrete lactoferrin. This molecule interacts with cells at inflammation sites to inhibit the production of cytokines that would cause inflammation. There is also some evidence that it inhibits the binding of viruses to cells, including HIV.

LF is used in the treatment of cystic fibrosis, a disease that affects many parts of the body, including the lungs. It causes mucus to build up in them, and susceptibility to disease is increased. Part of the reason for this increased vunerability is that components of the immune system, such as LF and hypothiocyanate, are produced at low levels or are lacking entirely. Hypothiocyanate is normally generated as an indirect result of lactoperoxidase activity, another protein that is involved in the respiratory tract antimicrobial defense system. A current treatment for cystic fibrosis involves treatment with LF and hypothiocyanate.

WiseGeek is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
Share
WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.

WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.