Heme and Non-heme Iron Intakes, Gut Microbiota, and Influence on Host Iron Absorption
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- This is an observational study: the protocol does not assign a study treatment.
- Who it may be relevant to
- Registry conditions: Anemia, Iron Deficiency, Iron Overload. Basic parameters: 18 years — 40 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- United States
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Overview
The FeMicrobiome study will evaluate gut microbiome features and their relationships with dietary iron absorption in healthy adults. The investigators hypothesize that (1) the gut microbiota can be shaped by the heme and non-heme Fe content of the diet and that (2) this will influence individual variation in dietary Fe absorption.
Detailed description
Iron is an essential micronutrient ingested as either heme iron (from animal products) or non-heme iron (from both plant and animal sources). Humans have no regulatable means of eliminating absorbed iron, necessitating tight control of dietary iron absorption. Likewise, native microbes have evolved efficient iron sensing and utilization pathways to scavenge iron from the gastrointestinal environment, resulting in a competition for iron between the host and their microbiota. As growing numbers of Americans adopt plant-based diets, heme iron intakes are markedly reduced. This may shift the gut microbiome as some gut microbiota cannot independently synthesize heme and require host dietary heme sources to support their heme-dependent functions. Animal data have recently discovered that other gut microbiota respond to a low iron. To date, significant knowledge gaps exist on the interplay between dietary iron sources, native gut microbes, and iron utilization in humans. In the FeMicrobiome study, study investigators will recruit 120 adults who habitually ingest plant-based diets or habitually ingest diets containing animal protein (e.g., beef, pork, chicken, fish, and seafood). Iron absorption will be measured by using an in vivo, functional approach based on stable iron isotopes (i.e., 57Fe). Study participants will consume 57Fe (as ferrous sulfate) in the fasted state followed by two standardized meals. Two weeks after iron dosing, a blood sample will be collected from each participant and the amount of 57Fe incorporated into red blood cells will be measured using magnetic sector thermal ionization mass spectrometry. A stool sample will be collected near the time of 57Fe consumption. DNA will be extracted from this stool sample and sequenced using a high-depth shotgun metagenomic approach.
Primary outcome measures
- The percent of non-heme iron absorption [Time frame: 2-week]
- The concentrations of hemoglobin [Time frame: baseline]
- The concentrations of ferritin [Time frame: baseline]
- Serum transferrin receptor [Time frame: baseline]
- The hematocrit [Time frame: baseline]
- Habitual dietary information [Time frame: baseline]
- Dietary information on the day prior to iron dosing [Time frame: baseline]
- Gut microbiome composition [Time frame: baseline]
Eligibility criteria
Inclusion criteria
- Healthy adults
- Age between 18- 40y
- Non-smoking
- Not currently taking vitamin, mineral, prebiotic, and probiotic supplements.
- Females: premenopausal and not pregnant or lactating
- No preexisting medical complications (such as eating disorders, hemoglobinopathies, malabsorption diseases, steroid use, substance abuse history, or taking medications known to influence iron homeostasis)
- Body mass index (BMI) between 18 - 27 kg/m2.
Exclusion criteria
- BMI <18 or > 27 kg/m2,
- Age <18 y or > 40y,
- Smoking
- Pregnancy, lactating
- Have gastrointestinal disorders/malabsorption diseases/hemoglobinopathies/dietary restrictions/steroid use/ medication use of medications known to impact iron status, iron utilization or inflammatory status
- Currently take vitamin, mineral, prebiotic, and probiotic supplements.
- Recently received antibiotic treatment
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Observational model
- Case-only
Study locations
United States · 1 center
- Cornell University — Ithaca
Identifiers
NCT: NCT06146608 · IRB0147198 · 2023-67017-39059