Lactoferrin
Identity, Nomenclature, and Natural Sources
Lactoferrin (LF), also known as lactotransferrin (LTF), is a multifunctional protein of the transferrin family. It is a globular glycoprotein with a molecular mass of approximately 80 kDa that is widely represented in various secretory fluids, such as milk, saliva, tears, and nasal secretions. As a major component of the mammalian innate immune system, lactoferrin is expressed in most biological fluids. Lactoferrin is also present in secondary granules of polymorphonuclear neutrophils (PMNs) and is secreted by some acinar cells.
The protein was extracted from milk, found to contain iron, and was structurally and chemically similar to serum transferrin. It was named lactoferrin in 1961, though the name lactotransferrin was used in some earlier publications. Human lactoferrin (hLF), isolated by Bengt Johannson in 1960, is made up of a single chain polypeptide of 691 amino acids. Bovine LF (bLF) was first isolated by Sørensen and Sørensen in 1939.
Concentrations by source:
- The concentration of lactoferrin in human milk is lactation-stage related; colostrum contains more than 5 g/L, which then significantly decreases to 2–3 g/L in mature milk.
- Human colostrum ("first milk") has the highest concentration, followed by human milk, then cow milk (150 mg/L).
- Lactoferrin is produced by epithelial cells of various organs and is present in most secretory fluids (0.001–6 g/L), including colostrum, milk, saliva, bile, gastric and intestinal juice, urine, and vaginal fluid.
Molecular Structure and Chemical Identity
X-ray diffraction reveals that lactoferrin is based on one polypeptide chain that contains about 700 amino acids and forms two homologous globular domains named N- and C-lobes. The N-lobe corresponds to amino acid residues 1–333 and the C-lobe to 345–692, with the ends connected by a short α-helix. Each lobe consists of two subdomains (N1, N2 and C1, C2) and contains one iron-binding site and one glycosylation site.
Lactoferrin exists in two forms: iron-rich hololactoferrin and iron-free apolactoferrin. Their tertiary structures differ; apolactoferrin is characterized by an "open" conformation of the N-lobe and a "closed" conformation of the C-lobe, while both lobes are closed in hololactoferrin. Each lactoferrin molecule can reversibly bind two ions of iron, zinc, copper, or other metals, with binding sites localized in each of the two protein globules. Each ion is bonded with six ligands: four from the polypeptide chain (two tyrosine residues, one histidine residue, and one aspartic acid residue) and two from carbonate or bicarbonate ions.
The degree of glycosylation of the protein may vary, causing the molecular weight of lactoferrin to range between 76 and 80 kDa. The stability of lactoferrin has been associated with its high degree of glycosylation. Lactoferrin belongs to the basic proteins, with an isoelectric point of 8.7.
Human LF (hLF) contains three potential N-glycosylation sites (Asn-138, Asn-479, and Asn-624), of which Asn-138 and Asn-479 are commonly glycosylated. In comparison, bovine LF (bLF) has five glycosylation sites, four of which are glycosylated (Asn-233, Asn-368, Asn-476, and Asn-545).
Common Forms and Preparations
Lactoferrin can be purified from milk or produced recombinantly. Ion-exchange, gel permeation, adsorption, and immunoaffinity chromatographic techniques have been utilized for the isolation of lactoferrin from milk or whey. The primary commercial forms include:
- Bovine lactoferrin (bLF): Bovine LF is currently generally recognized as safe (GRAS) in the US and may be added to non-exempt term infant formula, sports and functional foods, yogurt, ice cream, powdered milk, and chewing gum, and used as an antimicrobial agent.
- Recombinant human lactoferrin (rhLF): As an alternative source to bLF, recombinant human LF (rhLF) derived from transgenic rice and cows was evaluated as a food ingredient and went through the GRAS notification program in the mid-2000s. More recently, rhLF has been produced via precision fermentation in Komagataella phaffii (yeast).
- Lactoferricin and derived peptides: Thirty years ago, the first lactoferrin-derived peptide was isolated and showed higher antimicrobial activity than native lactoferrin — lactoferricin. The Lf-derived peptides Lf(1–11), lactoferricin (Lfcin), and lactoferrampin exhibit interesting and more potent antimicrobial actions than the intact protein.
- Colostrum-based preparations: Bovine colostrum has been used for hundreds of years as a traditional or complementary therapy. It is produced during the first few days after birth and contains high levels of immunoglobulins, antimicrobial peptides, and growth factors, including lactoferrin.
Lactoferrin's iron-binding bacteriostatic effect, coupled with its general abundance in breast milk, has led to numerous studies in newborn mammalian offspring, prompting its incorporation into Japanese baby formula since approximately 1993.
Traditional and Historical Use
Human beings have used lactoferrin for more time than modern science can document. As early as wartime in medieval Europe, knights used whey from colostrum to clean wounds caused by bows, arrows, and swords to avoid worsening infection.
The use of colostrum for both medicinal and spiritual purposes has been documented in traditional Ayurvedic medicine and among the ancient Hindu rishis (spiritual leaders) of India. At the turn of the 20th century, the use of colostrum was advocated to protect infants against both human and bovine infections. Prior to the advent of sulfa drugs and other antibiotics, colostrum was used to boost defense against immune diseases.
Albert Sabin isolated antipolio antibodies in bovine colostrum in the 1950s; the first experiments with hyperimmune colostrum were conducted in the 1960s. Lactoferrin was first formally described in breast milk by scientist Bengt Johansson in 1960. In 1971, RĂĽmke et al. first found that the content of lactoferrin in serum protein of cancer patients was elevated.
Key Constituents, Derived Compounds, and Mechanisms of Action
Iron Sequestration
Owing to its iron-binding properties, lactoferrin has been proposed to play a role in iron uptake by the intestinal mucosa and to act as a bacteriostatic agent by withholding iron from iron-requiring bacteria. The lactoferrin iron-binding ability also impacts immune homeostasis and lactoferrin's anti-inflammatory function. Since iron is crucial in modulating the production of reactive oxygen species (ROS), lactoferrin as an iron-binding protein can reduce oxidative stress caused by ROS and can thus control excessive inflammatory responses.
Direct Antimicrobial Activity
Antimicrobial effects are mediated by iron sequestration, disruption of microbial membranes, inhibition of microbial adhesion, and interference with host–pathogen interactions. Beyond its antimicrobial functions, Lf regulates pro- and anti-inflammatory mediators and mitigates excessive inflammation.
Lactoferrin's protective effects range from direct antimicrobial activities against a large panel of microorganisms, including bacteria, viruses, fungi, and parasites, to anti-inflammatory and anticancer activities. These extensive activities are made possible by mechanisms utilizing not only the capacity of LF to bind iron but also interactions of LF with molecular and cellular components of both host and pathogens.
Antifungal Activity
Lactoferrin exhibits notable antifungal activity through multiple mechanisms, including iron sequestration, disruption of fungal membrane integrity and increased membrane permeability, and the induction of apoptosis. LF has been shown to inhibit the growth of several pathogenic fungi, such as Aspergillus fumigatus, Candida spp., Cryptococcus neoformans, and Trichophyton mentagrophytes. Moreover, Lf acts synergistically with conventional antifungal agents, including amphotericin B, fluconazole, and caspofungin.
Antiviral Activity
The primary mechanism of lactoferrin's antiviral activity involves the direct interaction of Lf with viral proteins and host cell surface molecules that are targeted by viruses, thereby interfering with viral infection. Due to its cationic structure, Lf naturally interacts with certain host cell receptors, such as heparan sulfate proteoglycans, as well as viral particles and other receptors targeted by viruses. Therefore, Lf may interfere with virus-host cell interactions by acting as a receptor competitor for viruses.
Immunomodulatory Activity
Lactoferrin's presence in neutrophils and its release during inflammation suggest that lactoferrin is also involved in phagocytic killing and immune responses. Lactoferrin has a strong modulatory effect on the innate and adaptive immune responses by accelerating the maturation of T-cells and by differentiating immature B-cells. Moreover, during inflammation, lactoferrin exerts anti-inflammatory activity against IL-6.
Antioxidant Activity
Additionally, Lf alleviates oxidative stress by scavenging reactive oxygen species and enhancing antioxidant enzyme activity.
Lactoferricin: A Key Bioactive Peptide
Lactoferricins are bioactive natural antimicrobial peptides produced during digestion, comprising the N-terminal region of LF. In addition to their antiviral properties, lactoferricins are known for potent antimicrobial activities (antifungal, antibacterial, and antiparasitic), along with anti-inflammatory and immunomodulatory properties. Lactoferricin's net positive charge of 12+ allows for binding to bacterial membranes, with consequent destabilization and permeabilization of the bacterial membrane. Lactoferricin encompasses a large portion of the functional domain of the intact protein, and in many cases it not only retains the activities of LF but is more active. It possesses strong antimicrobial and weak antiviral activities, and also has potent antitumor and immunological properties.
Intestinal Epithelial and Microbiome Effects
Numerous studies have confirmed the beneficial effects of LF on the intestinal epithelium. This protein stimulates the growth, differentiation, and secretory activity of epithelial cells, which optimizes digestive processes and absorption of nutrients and protects against the action of pathogens and food allergens. LF also protects the intestinal epithelium from the toxic effects of reactive oxygen species, bacterial toxins, and xenobiotics such as NSAIDs.
Lactoferrin creates an environment for the growth of beneficial bacteria in the gut, thereby reducing the colonization of pathogenic bacteria. Furthermore, lactoferrin also modulates cytokines or chemokines produced by gut-associated lymphoid tissue cells, regulates innate and acquired immune pathways, and promotes neurodevelopment and intestinal maturation in preterm infants.
Scientific Evidence by Area of Use
1. Iron-Deficiency Anemia
This is among the most clinically studied areas for lactoferrin supplementation, with a substantial body of randomized controlled trial (RCT) and meta-analytic evidence.
Iron deficiency is among the most common dietary deficiencies in pregnancy and has high clinical significance, leading to the development of sideropenic anemia. Iron supplementation is recommended for pregnant women; however, dietary intake of iron from most commercially available formulas is often insufficient due to poor bioavailability, or has undesired gastrointestinal side effects.
A 2022 systematic review and meta-analysis published in Nutrients (PMC8838920) assessed comparative effects between oral lactoferrin and ferrous sulfate supplementation across multiple published intervention studies. A separate systematic review examining children included eleven studies (ten RCTs and one non-randomized trial). Serum ferritin and hemoglobin were found to be increased in groups treated with lactoferrin or a combination of lactoferrin and elemental iron compared to iron only or placebo supplementation. Adverse events such as constipation, vomiting, anorexia, and abdominal pain were found; particularly, a significant decrease in constipation was seen in lactoferrin-treated groups.
Lactoferrin is a multifunctional iron-binding glycoprotein that can modulate immunity, inflammation, and enhance iron absorption. Lactoferrin has been reported as an effective therapy in the treatment of anemia in both pediatrics and adults.
A 2022 RCT in children with inflammatory bowel disease-related iron-deficiency anemia (IBD-IDA) enrolled 80 children with IBD-related IDA; the ferrous sulfate group (46 children) received 6 mg/kg/day for 3 months, while the lactoferrin group (46 children) received bovine lactoferrin. Hemoglobin, mean corpuscular volume, serum iron, transferrin saturation, and serum ferritin significantly increased, while total iron-binding capacity decreased significantly after the administration of either ferrous sulfate or lactoferrin.
A 2024 meta-analysis synthesizing data from 19 randomized clinical trials involving 2,992 patients found that lactoferrin produced a statistically significant greater increase in hemoglobin compared to ferrous sulfate. The role of lactoferrin in iron absorption has been supported by several studies in non-pregnant women. Human recombinant lactoferrin produced in rice, applied via a standard breakfast meal, was as effective as ferrous sulfate in iron absorption by American young healthy women (n = 20).
Evidence strength: Moderate-to-strong. Multiple RCTs and meta-analyses in pregnant women and children support efficacy for improving hemoglobin and ferritin with fewer gastrointestinal side effects than ferrous sulfate. The underlying mechanism by which lactoferrin (itself too large to cross the gut barrier intact) enhances systemic iron status remains an area of ongoing research.
2. Immune Function and Respiratory Tract Infections
A 2022 systematic review aimed to identify all relevant publications and evaluate the effects of lactoferrin supplementation on inflammation, immune function, and respiratory tract infections (RTIs) in humans, including effects on systemic and airway inflammatory biomarkers, peripheral immune cell populations, and the incidence, duration, or severity of RTIs.
Eight out of thirteen studies in one meta-analysis reported improvements in at least one biomarker of immune function, and 6 of 8 studies reported improvements in biomarkers of immune function. All the trials included in this meta-analysis involved bovine lactoferrin in doses ranging from 32.4 mg/day to 3 g/day, and all trials except one were conducted in adults.
Evidence strength: Preliminary-to-moderate. Immunological biomarker improvements are consistently observed across short-term trials, but evidence for hard clinical endpoints (confirmed reductions in infection incidence) in healthy adults remains limited by small sample sizes and heterogeneity of study populations.
3. Neonatal Sepsis and Necrotizing Enterocolitis (NEC)
Lactoferrin, a milk glycoprotein with anti-inflammatory, immunomodulatory, and antimicrobial properties, has the potential to prevent infections in young children. A review found eleven registered clinical trials including more than 6,000 subjects. Despite small sample sizes in early trials, preliminary results showed a trend toward a positive protective effect of LF on neonatal infections.
The first demonstration of a reduction in the incidence of late-onset sepsis (LOS) in preterm infants with birth weight under 1,500 g was made using lactoferrin alone and/or in combination with Lactobacillus rhamnosus GG (LGG). Subsequently, bovine lactoferrin supplementation alone or in combination with LGG was shown to reduce the incidence of stage ≥2 NEC and of death and/or stage ≥2 NEC in preterm infants under 1,500 g. The most updated evidence from a Cochrane meta-analysis involving more than 5,200 preterm neonates highlighted the efficacy of lactoferrin for the prevention of late-onset sepsis (both bacterial and fungal) with or without probiotics. According to this study, lactoferrin also prevents urinary tract infections and decreases the length of hospital stay.
However, not all trials have confirmed this effect. One double-blind randomized controlled trial administered bovine lactoferrin (200 mg/kg/day) versus placebo for 8 weeks in 414 neonates with birth weights 500–2,000 g. Late-onset sepsis or sepsis-associated death occurred in 22 (10.5%) infants in the bovine lactoferrin group vs. 30 (14.6%) in the placebo group; there was no statistically significant difference after adjusting for hospital and birth weight (hazard ratio 0.73, 95% CI 0.42–1.26). For infants with birth weights <1,500 g, the hazard ratio was 0.69 (95% CI 0.39–1.25). Supplementation with bovine lactoferrin did not significantly reduce the incidence of sepsis in infants with birth weights <2,000 g.
Regarding treatment (as opposed to prevention) of neonatal sepsis and NEC: No eligible trials evaluating lactoferrin for the treatment of neonatal sepsis or NEC were identified in a Cochrane review. There is currently no evidence to support or refute the use of enteral lactoferrin, as an adjunct to antibiotic therapy, for the treatment of neonatal sepsis.
Evidence strength: Moderate for prevention of late-onset sepsis in preterm infants, supported by the Cochrane meta-analysis; however, at least one large, well-designed RCT was negative, and results are inconsistent across trials. Evidence for treatment is absent at the clinical trial level.
4. Helicobacter pylori Eradication
The concentrations of lactoferrin in the gastric juice and mucosa significantly increase during H. pylori infection and are strongly correlated with the severity of gastric mucosal inflammation. Numerous researchers have studied the antimicrobial properties of lactoferrin in vitro and in vivo. Recent studies have investigated the addition of oral lactoferrin supplementation to H. pylori eradication therapy, even though monotherapy with lactoferrin does not eradicate the microorganism.
In a meta-analysis of nine randomized trials (n = 1,343), pooled H. pylori eradication rates were 86.57% (95% CI = 83.99–89.15%) for patients receiving lactoferrin vs. 74.44% (95% CI = 71.14–77.74%) for those without, with an odds ratio of 2.26 (95% CI = 1.70–3.00). The occurrence of total side effects was 9.05% vs. 16.28% for groups with or without lactoferrin, respectively; the summary odds ratio for nausea was 0.15 (95% CI = 0.04–0.54). This review suggested that supplementation with lactoferrin could be effective in increasing eradication rates of anti-H. pylori therapy and could be considered helpful for patients with eradication failure. Furthermore, lactoferrin showed a positive impact on therapy-related side effects.
A subsequent randomized controlled trial enrolled 400 H. pylori-infected patients randomized into four equal groups, comparing proton pump inhibitor (PPI)-based triple therapy (PpTT) for 2 weeks, sequential therapy for 2 weeks, PpTT plus bovine lactoferrin for 2 weeks, and sequential therapy plus bovine lactoferrin for 2 weeks. Bovine lactoferrin addition to regimens of H. pylori treatment has been tried, with conflicting results.
Evidence strength: Moderate for lactoferrin as an adjunct (not monotherapy) in H. pylori eradication regimens; supported by a meta-analysis suggesting improved eradication rates and reduced side effects, though individual trials show conflicting results and overall quality is variable.
5. Acne Vulgaris and Dermatological Conditions
An improvement of dermatological lesions in patients with acne vulgaris was evidenced using 200 mg of lactoferrin daily for 12 weeks, with a reduction of inflammatory lesion count by 38.6%, total lesion count by 23.1%, and acne grade by 20.3%. A reduction of 31.1% in sebum content was also found.
An earlier open-label exploratory study enrolled subjects with mild-to-moderate acne vulgaris. Thirty-nine subjects, aged 17.5 ± 3.8 years, completed the study per protocol. At the end of the study (week 8), a mean reduction in non-inflammatory lesion count of 23.5% (p < 0.001) and in total lesion count was observed. The results for inflammatory acne lesions were variable. None of the subjects experienced a lactoferrin-related adverse event during the trial. Despite the limitations of an uncontrolled, open-label study, the results indicated that lactoferrin in mild-to-moderate acne vulgaris is well tolerated and may lead to overall improvement in acne lesion counts in the majority of affected adolescents and young adults when administered twice daily as a dietary supplement.
A systematic review of six clinical studies on lactoferrin in dermatology found encouraging evidence to suggest that lactoferrin may be beneficial in acne, psoriasis, and diabetic ulcerations.
Evidence strength: Preliminary. Results from small, mostly open-label trials are encouraging, but larger, adequately powered, placebo-controlled trials are needed to draw definitive conclusions.
6. Gastrointestinal Health, Microbiome, and Inflammatory Bowel Disease
Numerous studies have confirmed beneficial effects of LF on the intestinal epithelium, stimulating the growth, differentiation, and secretory activity of epithelial cells, which optimizes digestive processes and absorption of nutrients, and protects against pathogens and food allergens. LF also protects the intestinal epithelium from the toxic effects of reactive oxygen species, bacterial toxins, and xenobiotics such as NSAIDs. Importantly, LF also protects against gastrointestinal tract infections of viral, bacterial, fungal, and protozoal origin.
An oral combination of Lactobacillus acidophilus GLA-14, Lactobacillus rhamnosus HN001, and bovine lactoferrin was used in women with vulvovaginal candidiasis (VVC), demonstrating improvement of itching and discharge at 3 and 6 months compared with the placebo group. Moreover, the use of the same combination in women with bacterial vaginosis was associated with a decrease in symptoms such as vaginal discharge and itching.
Evidence strength: Moderate for gut-protective effects and microbiome modulation in neonates; preliminary in adult populations, with most mechanistic data derived from in vitro and animal models. Clinical IBD-related anemia trials show benefit but are small.
7. Antiviral Activity — Respiratory and Hepatotropic Viruses
Studies on competition between lactoferrin and SARS-CoV-2, Zika, Dengue, Hepatitis, and Influenza viruses have been conducted in vitro, demonstrating not only Lf's competitive binding properties but also its potential intracellular impact on host cells. It is critical to note that these are primarily in vitro findings; large-scale clinical trials in humans demonstrating antiviral benefit for these specific viral infections are, as of 2025, lacking or inconclusive.
An initial pilot clinical study demonstrated that lactoferrin could be one potential candidate as an anti-HCV reagent that may be effective for the treatment of chronic hepatitis C patients with low serum concentrations of HCV RNA. This represented early-phase clinical evidence only.
Evidence strength: Largely preclinical (in vitro, animal models). Human clinical data for antiviral applications remain limited and preliminary.
8. Bone Health
Research into lactoferrin's role in bone remodeling has been conducted, primarily in animal and cell-based models. Endogenous factors naturally occurring in the body have a lower risk of side effects and toxicity, making lactoferrin an object of study for potential adjunctive or alternative applications in metabolic bone disease. Robust, large-scale human RCT evidence for bone density endpoints has not yet been established at the same level as the iron or neonatal sepsis literature.
Evidence strength: Predominantly preclinical (animal models and cell studies); human clinical evidence is limited and insufficient for conclusions.
Body Systems and Health Areas of Association
- Innate Immune System: Lactoferrin is a major component of the mammalian innate immune system.
- Hematological / Iron Metabolism: Lactoferrin has been proposed to play a role in iron uptake by the intestinal mucosa and to act as a bacteriostatic agent by withholding iron from iron-requiring bacteria.
- Gastrointestinal Tract: LF stimulates the growth, differentiation, and secretory activity of intestinal epithelial cells and protects against bacterial toxins and NSAIDs.
- Neonatal and Pediatric Health: Supported by Cochrane-level evidence for prevention of late-onset neonatal sepsis.
- Mucosal Defense (respiratory, urogenital, ocular, oral): Lactoferrin exerts its effects on glandular epithelia, secretions, mucosal surfaces, the interstitium, and vascular compartments, participating in iron metabolism, disease defense, and modulation of inflammatory and immune responses.
- Dermatological: Preliminary evidence in acne vulgaris, psoriasis, and diabetic ulcerations.
- Skeletal: Early-phase research in bone remodeling and metabolic bone disease.
- Antimicrobial Defense: Lactoferrin is abundantly present in colostrum, secretory fluids, and neutrophil granules and exerts broad-spectrum antimicrobial activity against bacteria, viruses, fungi, and parasites, mediated by iron sequestration, disruption of microbial membranes, inhibition of microbial adhesion, and interference with host–pathogen interactions.
Dosage Forms and Doses Reported in Studies
Lactoferrin is available as an isolated dietary supplement (typically bovine lactoferrin powder or capsule) and as a component of bovine colostrum preparations. The following doses were reported in cited human studies and reviews:
- All trials in one immune-function meta-analysis involved bovine lactoferrin in doses ranging from 32.4 mg/day to 3 g/day; all trials except one were conducted in adults.
- A study of acne vulgaris used 200 mg of lactoferrin daily for 12 weeks.
- An open-label acne study used a twice-daily regimen of lactoferrin as a dietary supplement.
- One neonatal RCT randomized infants to receive either a placebo, 150 mg bovine lactoferrin, or 300 mg bovine lactoferrin orally for 28 days.
- Another neonatal double-blind RCT used bovine lactoferrin at 200 mg/kg/day versus placebo administered for 8 weeks.
- Research shows that taking lactoferrin 100 to 200 milligrams (mg) daily can increase iron levels in adults with low levels.
- For H. pylori eradication, supplemental lactoferrin was used alongside standard 2-week antibiotic regimens in the RCT of 400 patients.
No universal consensus on optimal dose or duration has been established, and doses vary substantially across indications in published literature.
Safety Considerations and Interactions
Regulatory Status
Bovine lactoferrin is currently generally recognized as safe (GRAS) in the US and may be added to non-exempt term infant formula, sports and functional foods, yogurt, ice cream, powdered milk, and chewing gum, and used as an antimicrobial agent. Bovine milk lactoferrin is generally recognized as safe (GRAS) in the United States for use in term infant formula, sports foods, functional foods, chewing gum, and as an antimicrobial agent.
Recombinant human lactoferrin derived from transgenic rice or cows was not permitted for commercial use as a food ingredient due to incomplete safety analysis of its effect on the immune system, including potential for alloimmunization and immunotoxicity.
Adverse Effects
Data from human studies were primarily reported as adverse events. They showed no or fewer lactoferrin-related adverse events compared to control and no evidence of toxicity, dose-limiting toxicities, or changes in iron status in various subpopulations. However, no human studies evaluated the immunomodulatory potential of recombinant human lactoferrin as a measure of safety.
In studies of children with iron-deficiency anemia, adverse events such as constipation, vomiting, anorexia, and abdominal pain were reported; however, a significant decrease in constipation was seen in lactoferrin-treated groups compared with ferrous sulfate.
In the neonatal supplementation RCT (n = 414), neonatal bovine lactoferrin supplementation had no adverse effects.
Allergy and Cow's Milk Protein Sensitivity
Preparations containing lactoferrin should not be taken in the case of suspected or diagnosed allergy to cow's milk proteins. Literature searches for human lactoferrin did not identify studies showing allergy to this protein; however, in rare cases, bovine lactoferrin is the target of IgE binding from those allergic to cow's milk outright or due to α-gal carbohydrate cross-reactivity.
Potential Immunogenicity of Recombinant Human Lactoferrin
A safety question related to the immunogenicity/alloimmunization potential of recombinant human lactoferrin was raised by an Expert Panel at the Toxicology Forum in 2008 and again in 2023, related to the exogenous nature of recombinant human lactoferrin. Alloimmunization is the breakdown of tolerance to a self-protein, with the potential to elicit an immune response leading to adverse events. This concern has not yet been fully resolved in clinical studies.
Gastrointestinal Tolerability Versus Standard Iron
Dietary intake of iron from most commercially available formulas is often insufficient due to iron-poor bioavailability or undesired side effects in the gastrointestinal tract. In multiple clinical trials, lactoferrin demonstrated a more favorable gastrointestinal side-effect profile compared with ferrous sulfate, particularly with respect to constipation.
Interaction with NSAIDs and Other Therapeutics
A 2023 comprehensive review examined the benefits of applying bovine colostrum and lactoferrin in animal models and clinical trials that included corticosteroid application, psychic stress, treatment with NSAIDs, and antibiotic use. The majority of investigations were performed with native bovine or recombinant human lactoferrin, applied alone or in combination with probiotics as nutraceuticals and dietary supplements. Apart from reducing adverse side effects of the applied therapeutics, bovine colostrum and lactoferrin augmented their efficacy and improved patient wellness.
Evidence Gaps and Limitations
Studies with lactoferrin mainly include tissue models and animal models, as well as clinical trials involving newborns, infants, and children. Certainty about its potential for adults remains limited. Supplementation in the adult general population still needs further detailed studies.
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