Do Iron Supplements Impact the Gut Microbiome of Women of Reproductive Age?

Anemia Clinical Trial

Official title:

Do Iron Supplements Impact the Gut Microbiome of Women of Reproductive Age?

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT05033483
• Other study ID #: Iron Mic
• Status: Completed
• Phase: N/A
• Start date: August 31, 2021
• Est. completion date: January 1, 2022

Study information

• Verified date: November 2021
• Source: South Australian Health and Medical Research Institute
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

In this randomised controlled trial the investigators will determine whether taking iron supplements compared to placebo for 21 days alters the bacteria (microbiome) in the large intestine of non-pregnant female participants.

Description:

BACKGROUND: Many women take iron-containing supplements during pregnancy. Indeed, the World Health Organization recommends that all pregnant women in low-income countries take an iron supplement containing 60 mg/day of elemental iron to reduce iron deficiency and iron-deficiency anaemia. However, oral iron has poor bioavailability, less than 10% absorbed with the remainder passing into the large intestine unbound, potentially providing a competitive advantage to iron-dependent opportunistic pathogens in the large intestine.

In a large randomized control trial in children, iron supplementation was shown to promote the growth of pathogenic species (E. coli, S. aureus, and L. monocytogenes) and inhibited the growth of commensal species (Lactobacillus and Bifidobacterium). These pathogens are associated with enteric infections, while the commensals act on the host's immune system to prevent colonization and invasion by pathogens.

It is NOT known if iron supplementation during pregnancy impacts the maternal and infant microbiome and, by extension, how this affects the neonatal risk of infection and immune dysregulation. Vertical transmission of the maternal microbiome to the newborn is a major determinant of infant health. If maternal iron supplementation affects the infant's health, strategies would be required to mitigate this risk.

The investigators require preliminary data to show how oral iron supplementation alters the intestinal microbiome in women. The Investigators will recruit non-pregnant female participants as there is no risk of vertical transmission to an infant in non-pregnant women. The investigators will conduct the study in Australia because there is not a natural abundance of pathogens that could potentially cause harm to the women. Nevertheless, the investigators would expect a shift in the microbiome from non-iron to iron, requiring bacterial species to return to baseline after women stop taking the iron.

HYPOTHESIS: Daily iron supplementation versus placebo for 21 days will alter the stool microbiome composition compared to placebo in non-pregnant female participants of reproductive age.

METHODS: 80 female participants (18-45 y) will be randomized to receive capsules containing iron (65.7 mg of elemental iron as ferrous fumarate) or placebo to take daily for 21 days. Stool samples will be collected at baseline, 21 days, and 42 days (washout).

Recruitment information / eligibility

• Status: Completed
• Enrollment: 82
• Est. completion date: January 1, 2022
• Est. primary completion date: November 6, 2021
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Female
• Age group: 18 Years to 45 Years

Eligibility

Inclusion Criteria:

• Able to give informed consent

Exclusion Criteria:

• Pregnant or breastfeeding.

• Planning on becoming pregnant

• Diagnosed with iron deficiency and/or anaemia in the previous three months

• Taken antibiotics in the past three months

• Taken iron containing supplements in the past three months

Related Conditions & MeSH terms

• Anemia
• Communicable Diseases
• Infections
• Iron-deficiency
• Microbial Colonization

Intervention

Dietary Supplement:
• Ferrous Fumarate
Gelatin capsule containing 200 mg ferrous fumarate and microcrystalline cellulose
• Placebo
Gelatin capsule containing microcrystalline cellulose

Locations

Country	Name	City	State
Australia	SAHMRI	Adelaide	South Australia

Sponsors (2)

Lead Sponsor	Collaborator
South Australian Health and Medical Research Institute	Flinders University

Country where clinical trial is conducted

Australia, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Weighted UniFrac dissimilarity score	Measure of microbiota beta-diversity	42 days (washout)
Other	Shannon-Wiener diversity	Microbiota alpha-diversity score with adjustment for baseline levels	42 days (washout)
Other	Bray-Curtis dissimilarity score	Measure of microbiota beta-diversity	42 days (washout)
Other	Faith's phylogenetic diversity	Microbiota alpha-diversity score with adjustment for baseline levels	42 days (washout)
Other	Taxonomic richness	Microbiota alpha-diversity score with adjustment for baseline levels	42 days (washout)
Other	Relative abundance of core bacterial taxa	Relative abundance of taxa present in >40% of baseline samples, with adjustment for baseline levels	42 days (washout)
Primary	Weighted UniFrac dissimilarity score	Measure of microbiota beta-diversity	21 days
Secondary	Bray-Curtis dissimilarity score	Measure of microbiota beta-diversity	21 days
Secondary	Shannon Wiener Diversity	Microbiota alpha-diversity score with adjustment for baseline levels	21 days
Secondary	Faith's phylogenetic diversity	Microbiota alpha-diversity score with adjustment for baseline levels	21 days
Secondary	Taxonomic richness	Microbiota alpha-diversity score with adjustment for baseline levels	21 days
Secondary	Relative abundance of core bacterial taxa	Relative abundance of taxa present in >40% of baseline samples, with adjustment for baseline levels	21 days