The Effect of Ovotransferrin and Lactoferrin on Iron Absorption From Ferrous Sulfate in Adult Women (OTf)

The Effect of Ovotransferrin and Lactoferrin on Iron Absorption From Ferrous Sulfate in Adult Women With Non-anemic Iron Deficiency: Stable Isotope Study

OTf is a monomeric glycoprotein of 686 amino acid residues and, as a member of the transferrin family, folds into two homologous globular lobes, each containing a single reversible Fe3 + binding site located within the interdomain cleft of each lobe. A comparison of apo (metal-free) and holostructures shows that iron binding or release in OTf occurs via a mechanism that involves opening or closing domains. human lactoferrin, transferrin, and OTf share the same reversible iron binding mechanism. Lactoferrin (Lf) is a 77 kDa glycosylated protein highly concentrated in human and bovine milk and can exist in an apo (metal free) state or can bind two ferric ions with very high affinity (k = 1022 M-1) forming holo-Lf . It has been recently reported that the addition of apo-Lf to a test meal containing FeSO4 significantly increased (+56%) iron absorption in young infants [19]. Despite these positive results in infants, to our knowledge, the ability of Lf to improve iron absorption from FeSO4 has not yet been assessed in adult women.

OTf and Lf will be tested as iron absorption enhancers by comparing the fractional iron absorption with that of FeSO4, the most widely used iron supplement. This study will provide information on how to improve iron absorption.In a randomized single-blind crossover study, the iron bioavailability is determined by means of stable iron isotope technology via the incorporation of stable isotopes from intrinsically labeled compounds into the erythrocytes 14 days after the study product.

Study Overview

• Status: Completed
• Conditions: Iron-deficiency
• Intervention / Treatment: Dietary supplement: FeSO4 + OTf; Dietary supplement: FeSO4 + Lf; Dietary supplement: FeSO4

Detailed Description

Iron deficiency remains a major public health problem in both developed and developing countries. At present, iron deficiency is mostly combated with iron supplements in the form of iron salts, especially iron sulfate. Iron salts are absorbed via the nonhemic iron route via the DMT-1 receptor, the rate of absorption being 20% of the total iron content. The dietary supplement industry tries to counteract this problem and to supply the required amount of iron by increasing the iron concentration in the dietary supplements in order to compensate for the low absorption rate. However, the high dosage of iron leads to side effects. It would be more effective to maximize iron absorption rather than a high dose of iron. Chicken protein ovotransferrin (OTf) is recognized as an iron-binding protein and a member of the transferrin family. OTf has amino acid sequences that are identical to chicken serum transferrin and shows approximately 50% homology with mammalian transferrin and lactoferrin. Despite its iron binding properties and safety for human consumption, no studies have evaluated OTf as an enhancer of iron absorption in humans.

OTf is a monomeric glycoprotein of 686 amino acid residues and, as a member of the transferrin family, folds into two homologous globular lobes, each containing a single reversible Fe3 + binding site located within the interdomain cleft of each lobe. A comparison of apo (metal-free) and holostructures shows that iron binding or release in OTf occurs via a mechanism that involves opening or closing domains. human lactoferrin, transferrin, and OTf share the same reversible iron binding mechanism.

Lactoferrin (Lf) is a 77 kDa glycosylated protein highly concentrated in human and bovine milk and can exist in an apo (metal free) state or can bind two ferric ions with very high affinity (k = 1022 M-1) forming holo-Lf . There are various studies that show the iron bioavailability of intrinsically labeled holo-Lf and apo- Lf and FeSO4. Lf appears to be a good source of bioavailable iron in both infants and in adults. Whether this is due to iron absorption through the Lf receptor and/or due to iron released from Lf joining the common non-heme iron pool and being subsequently absorbed, remains uncertain. The high affinity of OTf for iron (∼1030 M-1) at pH 7.5 implies that in presence of apo-OTf, iron will be sequestered. Lf also possesses the ability to bind iron (binding constants of ∼1022-1024 M-1) and retain it at lower pH. This difference in iron binding capacity, however, is not sufficient to establish conclusive statements regarding the activity of OTf in iron absorption.

It has been recently reported that the addition of apo-Lf to a test meal containing FeSO4 significantly increased (+56%) iron absorption in young infants. Despite these positive results in infants, to our knowledge, the ability of Lf to improve iron absorption from FeSO4 has not yet been assessed in adult women. Furthermore, despite its iron-binding properties and safety for human consumption, to the best of our knowledge, no studies have assessed OTf as an enhancer of iron absorption in humans. Therefore the use of OTf and Lf as iron absorption enhancers by comparing fractional iron absorption with that of FeSO4, the most commonly used iron supplement is investigated. This study will provide information regarding iron absorption enhancement, as well the behavior of OTf and Lf in adult women.

OTf and Lf will be tested as iron absorption enhancers by comparing the fractional iron absorption with that of FeSO4, the most widely used iron supplement. This study will provide information on how to improve iron absorption.In a randomized single-blind crossover study, the iron bioavailability is determined by means of stable iron isotope technology via the incorporation of stable isotopes from intrinsically labeled compounds into the erythrocytes 14 days after the study product.

Participants are given OTf, Lf and iron sulfate solutions. To quantify this, stable iron isotopes are used as marker substances. Stable isotopes exist in nature and in our body and there are no risks associated with their ingestion. No changes in the iron status of the subjects are expected during the study.35 women of childbearing age are being recruited for the study.

• Study Type: Interventional
• Enrollment (Actual): 35
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Switzerland
  • Zurich, Switzerland, 8092
    • ETH Zurich, Laboratory of Human Nutrition

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• female aged between 18-45 years old;
• SF <25 µg / L;
• BMI 18.5-24.9 kg / m2;
• weight <70 kg;
• signed informed consent;
• Able to communicate and comprehend English language.

Exclusion Criteria:

• Anemic (Hb <12 g / dL);
• inflammation (CRP> 5 mg / L);
• chronic digestive, renal and / or metabolic disease;
• chronic medications (except for oral contraceptives);
• use of vitamin, mineral and pre- and / or probiotic supplements in the previous 2 weeks and during the course of the study;
• blood transfusion, blood donation or significant blood loss over the past 4 months;
• difficulties with blood sampling;
• antibiotic treatment in the previous 4 weeks before the start of the study and during the course of the study;
• known hypersensitivity to egg;
• pregnancy (tested in serum at screening) or intention to become pregnant during the course of the study;
• lactation up to 6 weeks before study initiation;

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: OTf + FeSO4; OTf + FeSO4 - This is the experimental arm where Ferrous sulfate will be given to the participants along with apo-Ovotransferrin, a potential iron absorption enhancer. They will be given as solutions that will be spread on bread with butter and honey, a breakfast meal.	Dietary supplement: FeSO4 + OTf; OTf (apo ovotransferrin) + FeSO4
Other: Lf+ FeSO4; Lf + FeSO4 - This is the experimental arm where Ferrous sulfate will be given to the participants along with lactoferrin, a potential iron absorption enhancer. They will be given as solutions that will be spread on bread with butter and honey, a breakfast meal.	Dietary supplement: FeSO4 + Lf; Lf (lactoferrin) + FeSO4
Other: FeSO4; FeSO4 - This is the control arm where Ferrous sulfate will be given in the form of a solution that will be spread on bread with butter and honey, as a breakfast meal	Dietary supplement: FeSO4; Ferrous sulfate

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fractional iron absorption	The primary outcome is iron bioavailability (as measured by erythrocyte incorporation of the stable isotope labels) from the 2 different conditions in the standardized test meals.	Day 19th of the study

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Hemoglobin (Hb)	Iron status marker	Screening (-14,) day 1 and day 19th
Serum ferritin (SF)	Iron status marker	Screening (-14,) day 1 and day 19th
Serum transferrin receptor (sTfR),	Iron status marker	Screening (-14,) day 1 and day 19th
C-reactive protein (CRP)	Inflammation status	Screening (-14,) day 1 and day 19th

Collaborators and Investigators

• Sponsor: Swiss Federal Institute of Technology
• Investigators: Principal Investigator: Jessica Rigutto-Farebrother, PhD, Laboratory of Human Nutrition ETH Zürich

Study record dates

Study Major Dates

• Study Start (Actual): April 25, 2022
• Primary Completion (Actual): May 20, 2022
• Study Completion (Actual): May 20, 2022

Study Registration Dates

• First Submitted: October 29, 2021
• First Submitted That Met QC Criteria: February 9, 2022
• First Posted (Actual): February 10, 2022

Study Record Updates

• Last Update Posted (Actual): June 10, 2022
• Last Update Submitted That Met QC Criteria: June 9, 2022
• Last Verified: June 1, 2022

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Metabolic Diseases; Hematologic Diseases; Anemia, Hypochromic; Anemia; Iron Metabolism Disorders; Anemia, Iron-Deficiency; Physiological Effects of Drugs; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Muscarinic Antagonists; Cholinergic Antagonists; Cholinergic Agents; Urological Agents; Fesoterodine
• Other Study ID Numbers: OTf

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