The effects of orally administered lactoferrin in the prevention and management of viral infections Original paper
Researched by:
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Divine Aleru
ID
Divine Aleru
I am a biochemist with a deep curiosity for the human microbiome and how it shapes human health, and I enjoy making microbiome science more accessible through research and writing. With 2 years experience in microbiome research, I have curated microbiome studies, analyzed microbial signatures, and now focus on interventions as a Microbiome Signatures and Interventions Research Coordinator.
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Divine Aleru
Researched by:
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Divine Aleru
ID
Divine Aleru
Microbiome Signatures identifies and validates condition-specific microbiome shifts and interventions to accelerate clinical translation. Our multidisciplinary team supports clinicians, researchers, and innovators in turning microbiome science into actionable medicine.
Divine Aleru
What was reviewed?
This systematic review analyzed the antiviral efficacy of orally administered lactoferrin (LF) in human clinical studies. The review encompassed 27 records, including randomized controlled trials, non-randomized trials, and clinical trial protocols, with a focus on various viral infections such as hepatitis C virus (HCV), HIV, SARS-CoV-2, norovirus, rotavirus, and others. The primary goal was to evaluate LF’s role in the prevention or management of confirmed viral infections and to assess clinical and immunological outcomes from oral LF interventions across diverse populations.
Who was reviewed?
Participants included both adults and children across multiple studies involving infections from Flaviviridae (HCV), Retroviridae (HIV), Coronaviridae (SARS-CoV-2), Caliciviridae (norovirus), and Reoviridae (rotavirus). Most studies were conducted in Japan and Italy. Clinical populations ranged from healthy children to immunocompromised individuals and patients with chronic viral conditions. The review incorporated a diverse array of LF sources (e.g., bovine LF, recombinant human LF) and dosages, with durations ranging from 10 days to 15 months.
What were the most important findings?
Findings were highly heterogeneous and largely inconclusive. Some studies reported modest benefits in reducing viral loads (notably in low HCV baseline patients), symptom duration (especially in rotavirus and norovirus infections), and certain immunological markers like IL-6 or CD4+ percentages. However, these effects were not consistent across studies or virus families. For SARS-CoV-2, one preprint study reported shortened PCR conversion time and symptom duration, while another observed symptomatic relief with no significant virological changes. Importantly, lactoferrin showed a strong safety profile with minimal adverse effects, making it a candidate for further investigation.
From a microbiome perspective, oral LF may help preserve epithelial integrity and modulate mucosal immunity during viral infections, though direct evidence of microbiome modulation was lacking in this review. Studies on HIV noted trends in immune modulation, such as skewed T-cell populations and increased phagocytic activity, which suggest lactoferrin’s potential to stabilize host immune-microbial interactions indirectly.
What are the implications of this review?
Despite a promising in vitro profile, clinical evidence for oral lactoferrin’s antiviral efficacy remains inconclusive due to poor methodological quality, inconsistent dosing, and heterogeneous protocols across studies. Nonetheless, its safety, tolerability, and hints of symptom alleviation support its exploration as a supportive therapy—especially for viral infections where mucosal integrity and immune tolerance are compromised. For clinicians considering microbiome-centered interventions, lactoferrin’s potential to reduce infection-related inflammation without disrupting microbial communities is an attractive, albeit under-validated, approach.