Effects of Lactoferrin-enriched Whey on Iron Status in Females

BACKGROUND AND SIGNIFICANCE

Iron deficiency is a major cause of disease burden worldwide, affecting 1-2 billion people globally. While often considered an issue in developing nations, low iron intake is a growing problem in the US and other industrialized nations, particularly affecting women of reproductive age. In the US, 20% of women aged 18-45 have insufficient iron intake (below the EAR of 18 mg/day) and this number that has been growing over the last decades. This is, in part, due to reduced concentrations in foods and lower intakes of iron-containing foods. Moreover, iron-rich food sources also contain vitamin B12, which is an important co-factor in iron metabolism.

There is, therefore, a strong need to develop strategies that can improve iron status in women of reproductive age, given the generally low intakes of iron-containing sources in this demographic. Besides increasing iron intake, a promising strategy to improve iron status is to ingest compounds that can promote iron uptake. A particularly promising compound to increase iron uptake is lactoferrin.

Lactoferrin (LF) is an iron-binding glycoprotein enriched in mammalian milk. LF binds iron with exceptionally high affinity and is transferred via a variety of receptors into and between cells, serum, bile, and cerebrospinal fluid. It also has important immunological properties, particularly being anti-inflammatory and anti-viral.

LF supplementation has shown initial promise for enhancing iron status in women of reproductive age. A previous study on female long-distance runners, a group at heightened risk for iron-deficiency anemia, found that the combined supplementation of lactoferrin and iron was able to maintain serum ferritin (an indicator of iron status) and red blood cell counts, whereas supplementation with iron alone did not maintain serum ferritin levels and red blood cell counts during the 8-week training period.

To ensure proper absorption, LF is best ingested in a dairy matrix. That is because of the presence of an LF receptor in the human small intestine that can bind bovine LF, likely preventing the use of iron by gut pathogens. This, in turn, results in enhanced systemic availability of iron where it can exert beneficial tissue effects and contribute to adequate iron status.

There is also evidence from in vitro work to suggest that lactoferrin can have anti-inflammatory properties, which could further improve serum iron and hemoglobin concentrations as inflammation negatively impacts iron metabolism. However, more clinical nutrition work is certainly needed to study these potential beneficial effects of LF.

1. STUDY OBJECTIVES
2. To determine the effects of lactoferrin \& iron supplementation in whey protein matrix on markers of iron absorption (serum ferritin) compared to a lactoferrin, iron, vitamin b12 and non-milk protein control (rice protein) and a lactoferrin, iron, vitamin b12 control without protein (maltodextrin).
3. To determine the effects of lactoferrin \& iron supplementation in whey protein matrix on markers of iron metabolism (RBC, Hb, Hc) compared to a lactoferrin, iron, vitamin b12 and non-milk protein control (rice protein) and a lactoferrin, iron, vitamin b12 control without protein (maltodextrin).
4. To determine the effects of lactoferrin \& iron supplementation in whey protein matrix on plasma inflammatory markers (IL-6, TNF-α, and C-reactive protein) compared to a lactoferrin, iron, vitamin b12 and non-milk protein control (rice protein) and a lactoferrin, iron, vitamin b12 control without protein (maltodextrin).
5. DESIGN AND PROCEDURES

3.1 Study duration Participant involvement will be 17 weeks. Week one, participants will go through the initial screening process. participants will consume two servings of supplement per day for the remaining 16 weeks.

3.2 Participants We will recruit 90 physically active female participants between 18-30 yrs, who are physically active (>2 days/week) with a BMI ≥18 and ≤30 kg/m2.

3.3 Description of study visits

Pre-screening (week 1. 15 minutes): Interested participants will have access to the informed consent via a link to recruitment materials. Participants that reach out via email or phone will be provided with a REDCap survey link to the screening questions that asks them further details about their health, diet, and sleep (see inclusion/exclusion criteria). Only minimum personal health information will be collected to determine eligibility. Responses will be reviewed by a study team member (all study team members will have completed the necessary CITI training) and potentially eligible candidates will be contacted to schedule a consent/screening visit. The pre-screen is to confirm that the participant meets most of the criteria before the subject is scheduled for a consent meeting. This will limit subject and research staff time burden. Information gathered will not be attached to identifiers and will be deleted if they decide to not participate or do not meet criteria. If participants screen as a "maybe", they will be contacted by phone or email with follow up questions to determine eligibility. Participants who are taking some medications that may interfere, but who are willing to stop cease usage will require a doctor's release to stop taking prescription medications.

Consent (Week 1. Duration: 1 hour): This visit will take place at the Center for Human Nutrition Studies or will happen virtually (via a tele-call platform such as Zoom). This visit will include the following. Participants will review the consent document with a member of the study team; once all questions have been satisfactorily answered, participants will be asked to sign and date the consent form if participants wish to participate in the study. Participants will be asked to sign the consent form electronically through REDCap using a unique link that is provided to them.

When deemed eligible and contacted, participants can combine the consent visit with the screening visit described below. If participants wish to do so, participants will be asked to come to the Center for Human Nutrition Studies in the morning after an overnight fast, requiring them not to eat or chew gum (nothing but water) 12 hours prior to their arrival. This information will not apply if the investigators do a virtual consent visit first. If participants agree to participate, they will come for the in-person screening visit.

Initial Screening Visit (Week 1. Duration: 1 hour): Assuming participants pre-qualify for the study, and are interested in participating, they will undergo an in-person screening visit. This visit will take place at the Center for Human Nutrition Studies. This visit will be performed in the morning, will last approximately 1 hour, and requires participants not to eat anything or chew gum (nothing but water) for 12 hours prior to their arrival time. This visit will include the following:

• Body mass and height: The investigators will measure their height and body weight to determine their body mass index.
• Blood draw: Participants will have blood drawn from a forearm or hand vein for routine lab analyses (basic metabolic panel and lipid panel), hemoglobinA1c and serum ferritin. The amount drawn will be 15 mL (1 tablespoon) total. If they are of childbearing potential, a pregnancy test will be performed as part of this screening blood draw. It must be negative to participate in this study.
• Questionnaires: If participants agree to participate, participants will be emailed a link with questionnaires to fill out. These questionnaires will ask detailed questions about their diet (7-day food log), potential GI responses such as abdominal discomfort, diarrhea, constipation, gas and bloating using The Gastrointestinal Symptom Rating Scale (GSRS), sleep such as duration and quality, and physical activity patterns, which are part of the screening and/or study process.
• Blood pressure: A blood pressure measurement will be taken using an automated upper arm blood pressure monitor. A total of three measurements will be taken.

Intervention Assignment and Intervention (Week 2 - 17. Duration: 10 min per week): If participants meet the inclusion criteria, participants will be randomly assigned to one of three groups for the duration of the study. The group assignment is random (like the flip of a coin) and participants will not know which group participants are in.

• Lactoferrin in whey group: If participants have been randomly assigned to the lactoferrin in whey protein group, participants they will receive weekly allotments of whey protein concentrate enriched with lactoferrin (a protein found in milk; 200 mg/serving), vitamin B12 (5.2µg/serving) and iron (6 mg/serving). This supplement will come in a flavored powder packaged individually in sachets.
• Lactoferrin alone group: If participants have been randomly assigned to the lactoferrin alone group, they will receive weekly allotments of maltodextrin enriched with B12 (5.2µg/serving), lactoferrin (200mg/serving) and iron (6 mg/serving). This supplement will come in the form of a flavored powder and each serving will be packaged individually in sachets.
• Rice protein group: If participants have been randomly assigned to the whey protein group, they will receive weekly allotments of rice protein concentrate enriched with B12 (5.2µg/serving) and iron (6 mg/serving). This supplement will come in the form of a flavored powder and each serving will be packaged individually in sachets.
• Supplementation schedule: Participants will be asked to take their assigned supplement twice daily, once 30 min before their morning meal, and once between lunch and dinner.
• Weekly pickup: Participants will be asked to pick up the assigned protein supplements at the Center for Human Nutrition Studies once weekly and return the used sachets for record keeping at this visit. They will also be asked to complete questionnaires once weekly regarding GI responses, sleep, and physical activity patterns.
• Tracking: Participants will be asked to mark the time and date that participants take their assigned supplements in an online database called REDcap (described below) so that the research team can determine compliance and provide reminders if necessary.

Mid intervention check-in (Week 9. Duration: 1 hour):

• Questionnaires: 7-day food log The questionnaire will include a 7-day recall of food consumed over the last week including what foods, how much and at about what time.

Final visit (Week 17. Duration: 1 hour): This visit will take place at the Center for Human Nutrition Studies. This visit will be performed in the morning, will last approximately 1 hour, and requires participants not to eat anything or chew gum (nothing but water) for 12 hours prior to their arrival time. This visit will include the following:

• Body mass and height: The investigators will measure their height and body weight to determine their body mass index.
• Blood draw: Participants will have blood drawn from a forearm or hand vein for routine lab analyses and iron status. The amount drawn will be 30 mL (2 tablespoon) total.
• Questionnaires: These questionnaires will ask detailed questions about their diet (7-day food log), GI responses, sleep, and physical activity patterns.
• Blood pressure: A blood pressure measurement will be taken using an automated upper arm blood pressure monitor. A total of three measurements will be taken.