Study of Dietary Heme and Non-heme Iron, Gut Microbiome, and Their Impact on Iron Absorption in Healthy Adults Aged 18 to 40

What this Trial Is About

This research investigates how different types of dietary iron, heme from animal products and non-heme from both plants and animals, affect the gut microbiome and iron absorption in healthy adults aged 18 to 40. The study aims to understand how the gut bacteria and dietary iron interact, especially as more people adopt plant-based diets that reduce heme iron intake. Researchers will explore how these changes influence individual differences in iron absorption, addressing important gaps in knowledge about iron and gut microbes in humans. Participants will be recruited based on their usual diet, either plant-based or containing animal protein. Each participant will consume a dose of stable isotope-labeled iron 57Fe in a fasting state, followed by two standardized meals. Two weeks later, blood samples will be taken to measure how much 57Fe has been absorbed into red blood cells. Around the time they consume the iron dose, participants will also provide a stool sample for detailed gut microbiome analysis using DNA sequencing methods. During the study, various assessments will be done including measuring blood markers like hemoglobin, ferritin, transferrin receptor, and hematocrit at baseline. Dietary information will be collected both at baseline and on the day before iron dosing. The gut microbiome composition will be analyzed from stool samples. The primary outcomes focus on the percentage of non-heme iron absorbed after two weeks and baseline blood and dietary measures. This observational study is conducted by Cornell University and involves healthy adult volunteers with no major health issues affecting iron metabolism.

Heme and Non-heme Iron Intakes, Gut Microbiota, and Influence on Host Iron Absorption