Lactoferrin for prevention of common viral infections Original paper

What was reviewed?

This review evaluated both in vitro and in vivo evidence for lactoferrin’s antiviral activity against common viral infections, particularly respiratory viruses, gastroenteritis viruses, summer cold-related viruses, and herpes viruses. It focused on the efficacy of oral administration of bovine and human lactoferrin in reducing infection rates, severity of symptoms, and host immune responses in animal models and human studies.

Who was reviewed?

The authors synthesized findings from multiple cell-based assays, murine models, and clinical studies in human populations across all age groups. Viral targets included influenza A, respiratory syncytial virus (RSV), parainfluenza virus, rotavirus, norovirus, enterovirus 71, coxsackievirus, adenovirus, and herpes simplex virus types 1 and 2. Study populations encompassed both healthy individuals and those affected by viral illness, with a particular focus on children and immunocompromised patients.

What were the most important findings?

Lactoferrin showed consistent in vitro inhibition of viral attachment and entry across a wide range of viruses by binding to cellular receptors or directly to viral particles. In vivo, orally administered lactoferrin reduced the incidence or severity of common cold symptoms, gastroenteritis episodes, and herpes infections in some clinical cohorts. In norovirus and rotavirus infections, lactoferrin limited disease severity rather than preventing infection outright. Mechanistically, lactoferrin induced interferon-α/β expression and activated natural killer (NK) cells and Th1 cytokines such as IL-12 and IFN-γ, providing mucosal and systemic immune enhancement.

Relevance to microbiome health emerges through lactoferrin’s non-bactericidal antiviral action and immunomodulatory roles. By limiting epithelial inflammation and promoting immune homeostasis without disrupting microbial communities, lactoferrin indirectly supports a balanced mucosal microbiome. This is particularly significant in viral gastroenteritis, where microbial dysbiosis often follows mucosal damage. Lactoferrin’s ability to prevent viral entry and reduce cytokine-driven inflammation positions it as a microbiome-preserving antiviral adjunct.

What are the implications of this review?

Lactoferrin holds promise as a preventive agent for common viral infections, especially in settings lacking specific antiviral drugs, such as noroviral gastroenteritis. Its ability to modulate immune responses, reduce viral replication, and support epithelial barrier functions suggests a valuable role in microbiome-aligned therapies. However, researchers observe varying outcomes depending on dosage, viral target, and population, and emphasize the need for further controlled human studies. Still, the safety, accessibility, and immunonutritional value of lactoferrin argue strongly for its inclusion in functional food strategies aimed at infection prevention and mucosal immune support.