Absorption of Iron From Stabilized Lactoferrin: A Study in Women With Iron Deficiency (LOBSTER)

Iron Absorption From Stabilized Lactoferrin: An Experimental Study in Iron Deficient Women (LOBSTER)

Lactoferrin (LF) is a natural iron-binding protein found in milk. It exists either in an iron-free state (apo-LF) or bound to iron (holo-LF). Whether LF binds iron to facilitate its absorption and/or to sequester iron from potential enteropathogens remains uncertain. However, while LF is a promising tool for treating iron deficiency, it is sensitive to heat during food processing and to the acidic environment of the human stomach. This degradation often causes LF to lose its functional properties before it can promote iron absorption effectively.

This study aims to evaluate whether encapsulating apo-LF (either alone or in combination with iron) can protect LF from digestion and enhance iron absorption. Using a randomized, crossover design, different encapsulation methods will be compared to determine which results in the highest iron absorption in women with iron deficiency.

All test compounds will be labeled with stable iron isotopes. Participants will consume the labeled compounds with a test meal or water in a randomized order, allowing for within subject comparisons. Fractional iron absorption will be measured 17 days after administration via the incorporation of labeled iron into red blood cells.

Study Overview

• Status: Recruiting
• Conditions: Iron Deficiency (Without Anemia)
• Intervention / Treatment: Other: FeSO4 + meal-matrix; Other: FeSO4 + native LF + meal-matrix; Other: FeSO4 + NaCas-LF + meal-matrix; Other: NaCas-LF-Fe + meal-matrix; Other: FeSO4 + LMP-LF + meal-matrix; Other: LMP-LF-Fe + meal-matrix; Other: NaCas-LF-Fe + water; Other: LMP-LF-Fe + water; Other: FeSO4 + water

• Study Type: Interventional
• Enrollment (Estimated): 45
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Salome Häcki, MSc; Phone Number: +41 44 632 75 78; Email: lobsterstudy@pharma.ethz.ch

Study Locations

• Switzerland
  • Zurich, Switzerland, 8092
    • Recruiting
    • ETH Zurich, Laboratory of Clinical Biopharmacy
    • Contact: Salome Häcki, MSc; Phone Number: +41 44 632 75 78; Email: lobsterstudy@pharma.ethz.ch

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Serum ferritin < 45 µg/L (iron depleted)
• Body weight < 70 kg
• Body mass index 18,5 - 24,9 kg/m2 (normal weight)
• Hemoglobin (Hb) > 120 g/L (nonanemic)
• C-reactive protein (CRP) < 5 mg/L (no inflammation)

Exclusion Criteria:

• Pregnant or lactating
• Strictly vegan
• Cigarette smoking (> 1 cigarette / week)
• Gastrointestinal or metabolic disorders affecting iron absorption or metabolism
• Use of medication known to affect iron metabolism (oral contraceptives are allowed)
• Intake of vitamin and mineral supplements in the 2 weeks before study start and during the study
• Blood transfusion, blood donation, or significant blood loss during the previous 4 months
• once enrolled, inability to follow study procedures or major illness
• Participation in another study with investigational drug within the 30 days preceding and during the present study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

9

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Ferrous sulfate + inhibitory meal; 4 mg of iron (58Fe) as ferrous sulfate + inhibitory meal	Other: FeSO4 + meal-matrix; Maize porridge with labelled ferrous sulfate (58Fe)
Active Comparator: Ferrous sulfate + native LF + inhibitory meal; 4 mg iron (58Fe) as ferrous sulfate + native LF + inhibitory meal	Other: FeSO4 + native LF + meal-matrix; Maize porridge with labelled ferrous sulfate (58Fe) and lactoferrin
Experimental: Ferrous sulfate + encapsulated LF (sodium caseinate) + inhibitory meal; 4 mg iron (57Fe) as ferrous sulfate + sodium caseinate-LF + inhibitory meal	Other: FeSO4 + NaCas-LF + meal-matrix; Maize porridge with labelled ferrous sulfate (57Fe) and in sodium caseinate encapsulated lactoferrin
Experimental: Encapsulated LF-Fe (Sodium caseinate) + inhibitory meal; 4 mg of iron (54Fe) encapsulated with LF in sodium caseinate + inhibitory meal	Other: NaCas-LF-Fe + meal-matrix; Maize porridge with sodium caseinate-lactoferrin-Fe (intrinsically labeled with iron isotope 54)
Experimental: Ferrous sulfate + encapsulated LF (low methoxy pectin) + inhibitory meal; 4 mg of iron (54Fe) as ferrous sulfate + low methoxy pectin-LF + inhibitory meal	Other: FeSO4 + LMP-LF + meal-matrix; Maize porridge with labelled ferrous sulfate (54Fe) and low methoxy pectin lactoferrin
Experimental: Encapsulated LF-Fe (low methoxy pectin) + inhibitory meal; 4 mg of iron (57Fe) encapsulated with LF in low methoxy pectin + inhibitory meal	Other: LMP-LF-Fe + meal-matrix; Maize porridge with low methoxy pectin-lactoferrin-Fe (intrinsically labelled with iron isotope 57)
Experimental: Encapsulated LF-Fe (sodium caseinate) + water; 100 mg of iron encapsulated with LF in sodium caseinate + water	Other: NaCas-LF-Fe + water; Water with sodium caseinate-lactoferrin-Fe (intrinsically labelled with iron isotope 54Fe)
Experimental: Encapsulated LF-Fe (low methoxy pectin) + water; 100 mg of iron encapsulated with LF in low methoxy pectin + water	Other: LMP-LF-Fe + water; Water with low methoxy pectin-lactoferrin-Fe (intrinsically labelled with iron isotope 57Fe)
Active Comparator: Ferrous sulfate + water; 100 mg of iron as ferrous sulfate + water	Other: FeSO4 + water; Water with ferrous sulfate (labelled with iron isotope 58Fe)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fractional iron absorption (%)	Fractional iron absorption calculated as the percentage of the administered labelled iron dose incorporated into red blood cells. The calculation is based on the measured shift in iron isotope ratios in blood samples collected 17 days after intake compared to baseline.	Day 22
Fractional iron absorption (%)	Fractional iron absorption calculated as the percentage of the administered labelled iron dose incorporated into red blood cells. The calculation is based on the measured shift in iron isotope ratios in blood samples collected 17 days after intake compared to day 22.	Day 43
Fractional iron absorption (%)	Fractional iron absorption calculated as the percentage of the administered labelled iron dose incorporated into red blood cells. The calculation is based on the measured shift in iron isotope ratios in blood samples collected 17 days after intake compared to day 43.	Day 64

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Hemoglobin (g/dL)	Iron status marker	Day 1
Hemoglobin (g/dL)	Iron status marker	Day 22
Hemoglobin (g/dL)	Iron status marker	Day 43
Hemoglobin (g/dL)	Iron status marker	Day 64
Serum Ferritin (µg/L)	Iron status marker	Day 1
Serum Ferritin (µg/L)	Iron status marker	Day 22
Serum Ferritin (µg/L)	Iron status marker	Day 43
soluble Transferrin Receptor (mg/L)	Iron status marker	Day 1
soluble Transferrin Receptor (mg/L)	Iron status marker	Day 22
soluble Transferrin Receptor (mg/L)	Iron status marker	Day 43
C-reactive protein (mg/L)	Chronic inflammation marker	Day 1
C-reactive protein (mg/L)	Chronic inflammation marker	Day 22
C-reactive protein (mg/L)	Chronic inflammation marker	Day 43
Alpha-1-acid Glycoprotein (g/L)	Acute inflammation marker	Day 1
Alpha-1-acid Glycoprotein (g/L)	Acute inflammation marker	Day 22
Alpha-1-acid Glycoprotein (g/L)	Acute inflammation marker	Day 43

Collaborators and Investigators

• Sponsor: Nicole Stoffel
• Investigators: Principal Investigator: Nicole Ursula Stoffel, Prof., ETH Zurich

Study record dates

Study Major Dates

• Study Start (Estimated): February 17, 2026
• Primary Completion (Estimated): May 1, 2026
• Study Completion (Estimated): May 1, 2026

Study Registration Dates

• First Submitted: January 31, 2026
• First Submitted That Met QC Criteria: January 31, 2026
• First Posted (Actual): February 6, 2026

Study Record Updates

• Last Update Posted (Actual): February 12, 2026
• Last Update Submitted That Met QC Criteria: February 11, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Dietary Supplements; Lactoferrin; Iron Deficiency; Iron Absorption; Iron Bioavailability; Iron Fortification; Stable Iron Isotopes
• Additional Relevant MeSH Terms: Metabolic Diseases; Iron Metabolism Disorders; Nutritional and Metabolic Diseases; Iron Deficiencies; Inorganic Chemicals; Anions; Ions; Electrolytes; Hydroxides; Alkalies; Oxides; Oxygen Compounds; Water
• Other Study ID Numbers: LOBSTER

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No