What is the role of lactoferrin (Lf) in human health?

From the Guidelines

Lactoferrin is a naturally occurring protein found in milk and bodily secretions that has antimicrobial, anti-inflammatory, and immune-modulating properties, and its use as a supplement is generally considered safe, but pregnant women and those with specific medical conditions should consult healthcare providers before supplementing 1.

Key Points

• Lactoferrin is most abundant in colostrum (first milk) and is present in human breast milk, tears, saliva, and other secretions 1.
• As a supplement, lactoferrin is typically taken in doses ranging from 100-1000 mg daily, with most common recommendations being 250-500 mg once or twice daily 1.
• Lactoferrin works primarily by binding to iron, which prevents harmful bacteria from using this essential nutrient for growth, and it also directly disrupts bacterial cell membranes and can inhibit viral entry into cells 1.
• Research suggests potential benefits for immune support, gut health, iron regulation, and fighting infections 1.
• Side effects are generally minimal, though some people may experience digestive discomfort, and those with milk allergies should be cautious as lactoferrin is derived from milk proteins 1.

Clinical Use

• Fecal lactoferrin can be used as a biomarker to rule in or rule out moderate to severe endoscopic inflammation in patients with ulcerative colitis, but the certainty of evidence is very low due to inconsistency and imprecision 1.
• The use of fecal lactoferrin as a biomarker is not recommended in clinical practice due to the low certainty of evidence and the potential for false positive or false negative results 1.

Recommendations

• Lactoferrin supplementation should be considered on a case-by-case basis, taking into account the individual's medical history, current health status, and potential interactions with other medications or supplements 1.
• Pregnant women and those with specific medical conditions should consult healthcare providers before supplementing with lactoferrin 1.
• Further research is needed to fully understand the potential benefits and risks of lactoferrin supplementation and to establish clear guidelines for its use in clinical practice 1.

From the Research

Properties of Lactoferrin

• Lactoferrin is a multifunctional protein that exhibits anti-inflammatory, immune regulating, and anti-infective properties 2, 3
• It has the ability to chelate iron and interfere with the cellular receptors of pathogenic microorganisms and their hosts 3
• Lactoferrin is non-toxic and has good compatibility with other supplements 3

Immune System and Inflammation

• Lactoferrin may act as a natural mucosal barrier, preventing the spread, infection, and inflammation caused by coronavirus disease 2019 (COVID-19) 2
• It has been shown to reduce systemic inflammation, with a decrease in at least one systemic inflammatory biomarker in 61% of studies in adults 4
• Lactoferrin supplementation supports immune and antioxidant status in healthy human males, with statistically significant increases in total T-cell activation, helper T-cell activation, cytotoxic T-cell activation, and hydrophilic antioxidant capacity 5

Prevention and Treatment of Respiratory Tract Infections

• Lactoferrin has been shown to reduce the incidence, duration, or severity of respiratory tract infections (RTIs) in 60% of studies, with decreased incidence in 33% of studies, and either decreased frequency or duration in 50% of studies 4
• The combined use of lactoferrin and vitamin D could represent a valuable therapy for COVID-19 treatment and prevention, although further randomized clinical trials are needed 2, 6
• Lactoferrin supplementation may be a useful adjunct toward modulation of immune activity, in particular T-cell activation and antioxidant status 5

Potential Therapeutic Adjuvants

• Nutritional supplements with antimicrobial and immunomodulatory activity, including lactoferrin, are promising therapeutic adjuvants for the treatment of COVID-19, and also for the prevention of viral spreading 6
• The supplementation with lactoferrin, vitamin D, probiotics, and zinc could have a role both in preventing SARS-CoV-2 infection and in mitigating the clinical course in infected patients, contributing in the prevention of immune-mediated organ damage 6