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

From the Guidelines

Lactoferrin should not be used as a definitive diagnostic tool for ruling in or out moderate to severe endoscopically active disease in patients with ulcerative colitis due to its low sensitivity and specificity, as evidenced by a 2023 study published in Gastroenterology 1.

Key Points

• Lactoferrin has antimicrobial, antiviral, anti-inflammatory, and immunomodulatory properties, making it a potential supplement for immune support 1.
• The protein works by sequestering iron from pathogens, directly disrupting bacterial cell membranes, and regulating immune responses.
• However, its use as a biomarker for ulcerative colitis is limited due to low certainty of evidence supporting its accuracy in ruling in or out moderate to severe endoscopic inflammation 1.
• A 2023 study found that fecal lactoferrin had a sensitivity of 83% and specificity of 75% for detecting moderate to severe endoscopic activity, but the evidence was rated as very low certainty due to serious inconsistency and imprecision 1.
• Another study published in 2021 discussed the role of lactoferrin in iron homeostasis and its potential benefits in infant development, but this is not directly relevant to its use as a diagnostic tool for ulcerative colitis 1.
• The AGA suggests using either fecal calprotectin or fecal lactoferrin to screen for IBD, but with a conditional recommendation and low-quality evidence 1.

Recommendations

• Lactoferrin should be used with caution and in conjunction with other diagnostic tools when evaluating patients with ulcerative colitis, due to its limited accuracy and low certainty of evidence 1.
• Patients with milk allergies should use caution when considering lactoferrin supplementation, and it is advisable to consult a healthcare provider before starting supplementation, especially during pregnancy or when taking other medications.
• Further research is needed to fully understand the role of lactoferrin in ulcerative colitis and to determine its potential benefits and limitations as a diagnostic tool.

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 to the prevention of immune-mediated organ damage 6