The benefits of lactoferrin in the field of dental health

The oral cavity provides a rich environment for the most diverse and stable microbiome in the human body[1]. Like the gut microbiome, the oral flora is an essential part of the human innate immune system. The microorganisms present there determine the balance between pathological and physiological conditions, which can have both local and systemic effects [2,3].

Depending on the type of diet and other factors such as age and salivation, pathogens have an easy time disrupting the balance under certain circumstances. The resulting microbial dysbiosis can lead to oral diseases such as caries, gingivitis and periodontitis.

But there's more. Studies have shown that the oral microbiome can also be directly associated with the development or worsening of systemic infections, adverse pregnancy outcomes, cardiovascular disease, diabetes mellitus and autoimmune diseases [1,3].

The largest group of microorganisms in the mouth are bacteria, which can adhere in so-called biofilms (as plaque on the teeth) in the oral cavity [4]. Bacteria within a biofilm are significantly more tolerant to removal by the body's own cells (phagocytosis) or by removal by cells of the immune system (neutrophil granulocytes) [5].

With prolonged exposure, the plaque layer can mineralize and become tartar, often resulting in gingivitis, one of the most common diseases of the oral cavity [8].

The innate part of the immune system (Innate Immune System) provides numerous defense components to prevent pathogens from entering the body through the oral cavity. These include the mucosal barrier, as well as individual proteins found in body fluids, such as lysozyme and lactoferrin [10].

Therapeutic intervention in the oral cavity is a major challenge given the diversity of microorganisms present there and the delicate balance between these species.

As many antibacterial substances as there are, there are just as few that are able to dissolve a bacterial biofilm. Often this biofilm, such as on the teeth, can only be removed physically. It has already been shown that biofilms play a role in many diseases, from cancer [3], chronic back pain [11,12], Alzheimer's [13], asthma [9], to rheumatoid arthritis [9,14].

Lactoferrin, however, shows very efficient clearing of biofilms, even of environmentally resistant bacteria such as Pseudomonas aeruginosa and many oral pathogens [15].

A 2018 review sheds more light on the role of lactoferrin in the treatment of a wide range of oral and maxillofascial diseases [2].

Antibacterial effects

Lactoferrin showed very good effects against Streptococcus mutans, the main cause of caries, both during attachment and in the formation of biofilms.

In periodontitis, another manifestation of bacterial infections in the oral cavity, predominantly initiated by the gram-negative bacteria Porphyrornonas gingivalis.Porphyrornonas gingivalis and Prevotella intermedia, lactoferrin proved effective against both bacterial strains, albeit through slightly different mechanisms of action.

Antifungal effects

Candida albicans is the most common fungus in the oral cavity and can cause various systemic and localized diseases, such as oropharyngeal candidiasis. Lactoferrin has been shown to be very effective in inhibiting the growth of Candida albicans and could thus ensure less severe disease progression.

Antiviral effects

One of the most common viral infections of the oral mucosa is caused by the herpes virus. After the primary infection, it remains in the body and the infection can flare up again due to various provoking factors. Lactoferrin can intervene here by inhibiting binding to the surface of the host cell, replication and the spread from cell to cell.

One of the most common herpes viruses, the Epstein-Barr virus (EBV) also frequently affects the oropharyngeal region. As a result, symptoms such as an inflamed throat, swollen lymph nodes and a skin rash can occur in the head and neck area. If the host's immune system is already weakened, serious complications such as viral meningoencephalitis or myocarditis can also occur. Lactoferrin can prevent EBV from attaching to and entering the host cell and effectively inhibit cell transmission.

The Coxsackievirus A16 (CA16) causes the so-called hand-foot-and-mouth disease (HFMD). Studies have demonstrated the inhibitory effect of lactoferrin in the first phase of infection, as is the case with human papilloma virus (HPV).

Other therapeutic applications of lactoferrin in the oral cavity

• Dry mouth
• Bone regeneration in the event of damage around implants
• Prevention of inflammation in the implant area

A double-blind, randomized intervention study from 2019 investigated the use of a toothpaste containing enzymes and proteins, including lactoferrin, which mirrors their natural occurrence in saliva, to improve gum health [16]. Saliva plays an important role in maintaining the bacterial balance in the oral cavity with its components that belong to the humoral part of the innate immune system. After 4 weeks, it was shown that both plaque formation and the gingival index were significantly reduced.

Sources

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