Lactoferrin is part of the innate immune system of mammals, and is located in the external barriers of the body as a component of body fluids (breast milk, tears, saliva, sweat, etc.) [1,2]. In addition, it is present directly in white blood cells (immune cells) [3].

While the binding and release of iron is central to some of the biological functions of Lactoferrin [4], other activities are based on the interaction with molecular and cellular components [5-7].

Lactoferrin regulates the body’s immune cells (T-helper cells) so that a balance can be achieved [8,9]. The function of specific T-helper cells is particularly important for defence against viruses [10].

These immune regulating properties are explained by the ability of Lactoferrin to interact directly with receptors on the surface of immune cells [11-14] and thus positively affect both innate and acquired immunity.

The microbiome consists of about 100 trillion microorganisms and is a highly complex system. It is responsible for the effective provision of substances essential for life processes. Without a microbiome, there would be no life. Today, science is sure that most diseases of civilisation can be explained by a microbial imbalance in this non-human part of the body.

It can be assumed that Lactoferrin developed together with the human microbiome, and „learned“ to distinguish good bacteria from bad [15]. Lactoferrin does not attack beneficial microorganisms, it actually promotes their probiotic activity and, in this way, leads to a better, improved diversity within the microbiome. At the same time, the inflammatory tone is reduced – a reduced tendency to inflammation. The barrier membranes of the body are constantly interacting with the external environment which sometimes means a heavy work-load. Therefore, it is more than logical that Lactoferrin is firmly positioned there as part of the immune system’s first line of defence.