Lactoferrin supports the ‘innate’ or ‘general’ part of the immune system which is the body's first line of defence against germs entering the body. The second part of the immune system is the ‘adaptive’ or ‘specialized’ system which has stronger defence mechanisms.
The ‘innate’ system responds to all germs and foreign substances in exactly the same way, which is why it is sometimes referred to as the "nonspecific" immune system. It acts very quickly making sure that bacteria for example, that have entered the body are detected and destroyed on the spot within a few hours.
Lactoferrin’s main biological function is the binding and transport of iron, however Lactoferrin has also been shown to have antibacterial, antiviral and antifungal functions and properties.
By sequestering or ‘hiding away’ free iron, Lactoferrin removes the essential iron that bacteria need for growth. Lactoferrin also binds to substances known as lipopolysaccharides on bacterial walls. Through certain oxidative processes the bacterial membrane permeability is affected, resulting in the bacteria’s cell breakdown or lysis. Lactoferrin also prevents the attachment of the bacteria Helicobacter Pylori (H.Pylori) in the stomach, which in turn, aids in reducing digestive system disorders. Bovine Lactoferrin has a more potent effect against H. pylori than human Lactoferrin
The most studied mechanism of the antiviral activity of Lactoferrin, is its ability to divert virus particles from their target cells. Many viruses tend to bind to the lipoproteins (fatty molecules) of the cell membranes and then penetrate into the cell. Lactoferrin binds to the same particles, competing with and thereby repelling the virus particles. Lactoferrin also displays antiviral activity against both DNA- and RNA-viruses, including rotavirus, respiratory syncytial virus, herpes viruses and HIV. The antiviral effect of Lactoferrin begins in the early phase of infection. Again, Lactoferrin prevents entry of the virus in the host cell, either by blocking cellular receptors, or by direct binding to the virus particles.
Various antifungal functions of Lactoferrin have been reported including a wide spectrum of activity across yeasts including Candida Albicans and moulds. Research using Lactoferrin with other antifungal drugs in combination therapy have been studied with positive results. More recent studies now suggest that the main antifungal mechanism of Lactoferrin does not involve iron, rather it occurs through a direct interaction with the fungal cell surface, leading to cell membrane damage and leakage.