Lysine Intake for Breastfeeding

Overseen By Taylor Bailey, BSc

Age: 18 - 65

Sex: Female

Trial Phase: Academic

Sponsor: University of British Columbia

Must not be taking: Estrogen, Anti-dopaminergic, Methyldopa, others

Disqualifiers: Metabolic, Cardiovascular, Neurological, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 2

15 Participants Needed

Trial Summary

Will I have to stop taking my current medications?

Yes, you will need to stop taking medications that affect lactation or any continuous prescription medication to participate in this trial.

How does the drug lysine differ from other treatments for breastfeeding?

Lysine is unique because it is an amino acid that plays a crucial role in protein synthesis, which is important for milk production during breastfeeding. Unlike other treatments, lysine specifically supports the development of mammary glands and enhances milk protein synthesis, making it a novel approach for improving lactation. ^{1 2 3 4 5}

What is the purpose of this trial?

The study aims to establish lysine requirements using the indicator amino acid oxidation (IAAO) method in women exclusively breastfeeding a single infant aged 3-4 months, and how maternal lysine needs change once infant transition to complimentary feeding at a later age of 9-10 months. Each 8-hour study day will have an assigned test lysine intake ranging from deficient to excess. The diets will be provided in a complete protein shake format, meeting all nutrient requirements except for the test lysine intake. Breath samples evaluate the indicator's oxidation to determine protein synthesis in response to lysine intake. Urine and one blood sample will be collected to assess metabolite concentrations.

Research Team

Rajavel Elango

Principal Investigator

University of British Columbia

Eligibility Criteria

This trial is for women who are exclusively breastfeeding a single infant aged 3-4 months. It's also for those same mothers when their infants transition to complementary feeding at 9-10 months. Participants must be healthy with no dietary restrictions that could affect the study.

Inclusion Criteria

My baby is 9-10 months old and has started eating solid foods.

I am a healthy woman aged 20-40, exclusively breastfeeding a 3-4 month old baby.

Exclusion Criteria

I do not have serious health issues like heart, nerve, or immune system problems.

I have had breast surgery that could affect breastfeeding.

I am taking medication that could affect breastfeeding.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

1 hour

1 visit (in-person)

Study Day

Participants receive a test lysine intake ranging from deficient to excess, with diets provided in a complete protein shake format. Breath, urine, and blood samples are collected to assess lysine metabolism.

8 hours

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after each study day

1-2 weeks

Treatment Details

Interventions

• Lysine

Trial Overview The study is testing different levels of lysine, an important amino acid, in the diets of breastfeeding women. Using protein shakes with varying lysine content, researchers will measure how this affects protein synthesis and nutrition during lactation and after introducing solid foods to infants.

Participant Groups

Group I: Test Lysine Intake Experimental Treatment 1 Intervention

Randomly assigned one of 7 test lysine intakes that range from deficient to excess (12mg/kg/d to 84mg/kg/d). Participants may complete up to 4 study days, at different randomly assigned intakes.

Who Is Running the Clinical Trial?

University of British Columbia

Lead Sponsor

Trials

1,506

Recruited

2,528,000+

Canadian Institutes of Health Research (CIHR)

Collaborator

Trials

1,417

Recruited

26,550,000+

Findings from Research

L-lysine (Lys) significantly enhances cell viability and milk protein synthesis in bovine mammary epithelial cells (BMECs), with optimal concentrations (1.0 mmol/L) increasing cell viability by 17-47% and protein synthesis by 7-23%.

Lys promotes protein synthesis primarily by increasing the uptake through the ATB0,+ transporter and activating the mTOR and JAK2-STAT5 signaling pathways, indicating its critical role in amino acid nutrition for milk production.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Lysine Stimulates Protein Synthesis by Promoting the Expression of ATB0,+ and Activating the mTOR Pathway in Bovine Mammary Epithelial Cells. Lin, X., Li, S., Zou, Y., et al.[2023]

Lactating women showed a slower rate of protein turnover and lower lysine catabolism compared to non-lactating postpartum women, indicating metabolic adaptations during lactation.

The study suggests that an intake of 1.3 g protein/kg per day may be insufficient to meet the protein needs of lactating women, potentially affecting overall maternal protein metabolism.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Lysine and protein metabolism in the young lactating woman. Thomas, MR., Irving, CS., Reeds, PJ., et al.[2013]

Lysine uptake in the lactating rat mammary gland is time-dependent and can be inhibited by both cationic amino acids (like arginine and ornithine) and various neutral amino acids (such as methionine and leucine), indicating a complex interaction between different types of amino acids.

Cationic amino acids not only inhibit lysine uptake but also enhance its efflux from mammary tissue, suggesting that they may share a common transport mechanism that regulates lysine levels in the gland.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Lysine transport in lactating rat mammary tissue: evidence for an interaction between cationic and neutral amino acids. Shennan, DB., McNeillie, SA., Jamieson, EA., et al.[2013]

The study used a rapid, paired-tracer dilution technique to investigate how lysine is transported across the mammary epithelium in lactating rats, revealing that lysine transport is likely mediated by specific carriers influenced by extracellular lysine concentration.

Lysine uptake was inhibited by the presence of other amino acids like leucine and glutamine, suggesting that the transport system in the mammary tissue can also accept neutral amino acids, which may impact nutrient availability during lactation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Evidence for an interaction between cationic and neutral amino acids at the blood-facing aspect of the lactating rat mammary epithelium. Calvert, DT., Shennan, DB.[2019]

In a study involving lactating Holstein cows, increasing L-lysine infusion levels led to a linear increase in milk production and milk protein yield, indicating that lysine is a key amino acid for enhancing milk output.

The research estimated that to meet the lysine requirements for cows producing about 30 kg of milk daily, an additional 64 g of L-lysine per day is necessary, highlighting the importance of lysine in dairy cow nutrition for optimal milk production.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

An assessment of absorbable lysine requirements in lactating cows. King, KJ., Bergen, WG., Sniffen, CJ., et al.[2018]

References

1. United States pubmed.ncbi.nlm.nih.gov

Lysine Stimulates Protein Synthesis by Promoting the Expression of ATB0,+ and Activating the mTOR Pathway in Bovine Mammary Epithelial Cells. [2023]

2. England pubmed.ncbi.nlm.nih.gov

Lysine and protein metabolism in the young lactating woman. [2013]

3. England pubmed.ncbi.nlm.nih.gov

Lysine transport in lactating rat mammary tissue: evidence for an interaction between cationic and neutral amino acids. [2013]

4. England pubmed.ncbi.nlm.nih.gov

Evidence for an interaction between cationic and neutral amino acids at the blood-facing aspect of the lactating rat mammary epithelium. [2019]

5. United States pubmed.ncbi.nlm.nih.gov

An assessment of absorbable lysine requirements in lactating cows. [2018]