Lactoferrin is a protein belonging to the group of glycoproteins. It was isolated from the whey of cow’s milk and then from breast milk, where it is found in high proportion. It has the particularity that it binds to iron and that is why it is a family of transferrins.
The presence of iron explains much of its biological functions. It promotes intestinal health, has antimicrobial and antioxidant activity and activates the immune system. In addition, once digested, it forms peptides that are also involved in health functions.
This protein is so interesting that its properties have stimulated the interest of the pharmaceutical, biotechnology and food industries. If you want to know more about the benefits of lactoferrin, continue reading.
What is Lactoferrin?
Lactoferrin or Lf is a protein that was first isolated from cow’s milk and then from human milk. It was previously known as lactotransferrin and is now classified as a glycoprotein. That is, it is a protein linked to a carbohydrate and iron. When it is free of iron it is known as apolactoferrin.
It is found dissolved in whey and has been characterized as an iron vehicle for the cells of the body. It is shaped like a butterfly, with 2 lateral wings connected to a central region or hinge. Each wing is capable of binding an iron molecule.
Where does it come from?
Lactoferrin is found mainly in mature milk and in colostrum, which is the first milky secretion after childbirth. Values range from 7 grams per liter of colostrum to 1 gram per liter of mature milk.
In addition to milk, it is also found in blood plasma, neutrophils, saliva, bile, tears, and the pancreas. Some researchers maintain that 30% of the iron in breast milk is bound to lactoferrin.
At a commercial level, the main source of lactoferrin is whey from cow’s milk, since the availability of massive quantities favors obtaining it.
Health Benefits of Lactoferrin
Lactoferrin demonstrates a variety of properties that have favored its application in some products. Next, we will see its benefits.
1. Participates in iron metabolism
As explained, lactoferrin binds to 2 iron molecules and thus helps to transport it through the blood. This transport medium helps in the metabolism of iron. In general, Lf acts as a balance protein, which maintains the body’s self-regulation.
2. Antimicrobial effect
It is well documented that lactoferrin exerts antimicrobial activity on a wide variety of pathogens, including fungi, bacteria, and viruses. There are several reasons that explain it.
First of all, Lf acts as the first line of defense in the intestine and promotes the growth of probiotic bacteria, such as bifidobacteria and lactobacilli. Additionally, lactoferrin has the ability to sequester iron ions at sites of infection, depriving bacteria of an essential nutrient for growth.
On the other hand, Lf can bind to the outer membranes of some types of bacteria, changing their rigidity and destabilizing them. In this way, they inhibit their growth.
An antimicrobial effect of Lf against Helicobacter pylori strains has also been found. Other studies comment on its effect on some bacteria resistant to certain antibiotics, such as Klebsiella spp. and Staphylococcus aureus.
Many of the antimicrobial properties of Lf derive from the activity of the bioactive peptide known as lactoferricin or Lfcn. This peptide is obtained from the degradation of Lf by the enzyme pepsin. The Lfcn does not capture iron.
3. Immunomodulatory activity
Lactoferrin may support the proliferation, differentiation, and activation of cells of the immune system. In addition, it facilitates the recognition of certain antigens and the production of antibodies.
Specific receptors for Lf are found on lymphocytes, macrophages, and monocytes. It also participates in the regulation of the activity of natural killer cells, which are lymphocytes that destroy cells infected by pathogenic organisms and tumor cells.
Currently, it is recognized that Lf has the ability to induce the production of anti-inflammatory substances, such as interleukin. On the other hand, a group of experts maintains that the antimicrobial activity of lactoferrin can prevent the development of inflammation. In this way, it prevents subsequent tissue damage.
4. Antioxidant effect
The antioxidant activity related to lactoferrin is associated with its ability to capture iron ions. This mineral, in its ionic or unbound form, acts as an accelerator for oxidation-reduction reactions, in which free radicals are produced.
The researchers also report that free radicals generated during the inflammatory response can be neutralized by lactoferrin. In this way, it protects the cells of the immune system.
5. It could help in the treatment of some types of cancer
Some studies conclude that the ability of Lf to modulate proinflammatory cytokines is associated with its anticancer effect. On the other hand, it would favor the death of tumor cells by stimulating the cytotoxic activity of natural killers. However, more studies in humans are required to confirm these results.
What is the future of lactoferrin in human health?
Lactoferrin is known to play a crucial role against infections, inhibiting the replication of viruses such as HIV and others of the herpes family. Lf acts as a natural mucosal barrier, both respiratory and intestinal.
In an observational study, it was found that 75 patients with active COVID-19 infection recovered by ingesting a bovine lactoferrin nutritional syrup. The supplement contained 32 milligrams of Lf in 10 milliliters and 12 milligrams of vitamin C, with 10 milligrams of zinc.
Despite being a promising approach, more research is required to verify its antiviral activity in humans and in laboratory trials. Experts consider that it is imperative to continue with other evidence to have conclusive results.