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Effect of Inulin on Iron Absorption in Humans

This study has been completed.
Information provided by (Responsible Party):
Prof. Michael B. Zimmermann, Swiss Federal Institute of Technology Identifier:
First received: November 9, 2011
Last updated: June 6, 2013
Last verified: June 2013

Prebiotics are non-digestible food ingredients that beneficially affect the host by selectively stimulating the growth or activity of species in the colon that can improve host health.

Inulin-type fructans (inulin and oligofructose) are natural food ingredients with prebiotic activity. Fermentation of inulin and oligofructose by lactic acid producing bacteria results in an increase in bacterial biomass and the production of SCFA (acetate, propionate and butyrate), lactic acid and the gases CO2 and H2. They are naturally present in significant amounts in several vegetables such as garlic, artichoke, onion, asparagus, leek and wheat (1-4%). Based on consumption data, the daily intake of inulin in Europe varies between 3.2 and 11.3g mainly from wheat (2-7.8g/d). However, this might have changed recently since inulin and oligofructose are used by the food industry either as sucrose and fat replacements or due to their health benefits for the human host.

Several human absorption studies evaluated the effect of inulin/oligofructose on mineral absorption. It was shown that calcium and magnesium absorption was positively influenced. Until now, the positive effect on iron absorption was only shown in animals. The influence on human iron absorption was investigated twice. Both studies reported no effect of inulin/oligofructose on iron absorption, but this was most likely due to poorly conceived study designs.

The aim of the present study is to demonstrate that inulin consumption over several weeks can lead to enhanced iron absorption in humans under optimized conditions.

Condition Intervention
Iron Absorption
Gut Bacteria
Dietary Supplement: inulin
Dietary Supplement: maltodextrin

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double Blind (Participant, Investigator)
Primary Purpose: Treatment
Official Title: Inulin Modifies Gut Microbiota, Fecal Lactate Concentration and Fecal pH But Does Not Influence Iron Absorption in Women With Low Iron Status

Resource links provided by NLM:

MedlinePlus related topics: Iron
Drug Information available for: Inulin
U.S. FDA Resources

Further study details as provided by Swiss Federal Institute of Technology:

Primary Outcome Measures:
  • impact of inulin on iron absorption from standardized test meals, measured in humans by stable iron isotope technique [ Time Frame: 3 month ]

Secondary Outcome Measures:
  • impact of inulin on the concentration of gut microbiota (bifidobacteria and total bacteria), SCFA and fecal pH in human subjects [ Time Frame: 3 month ]
    Concentration of bifidobacteria, total bacteria, SCFA (acetate, propionate, butyrate, formate), lactate, and pH will be measured (in the fecal samples of study participants) and compared between baseline, inulin period and placebo period. The pH of fecal sqamples will be measured using a digital pH meter. HPLC measurements will be done for the determination of SCFA and lactate. DNA amplification and detection will be done by quantitative PCR.

Enrollment: 32
Study Start Date: August 2011
Study Completion Date: January 2012
Primary Completion Date: November 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: inulin Dietary Supplement: inulin
20g/day for 4 weeks
Placebo Comparator: maltodextrin Dietary Supplement: maltodextrin
20g/day for 4 weeks


Ages Eligible for Study:   18 Years to 40 Years   (Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • non-pregnant, non-lactating women
  • between 18 and 40 years
  • below 65kg

Exclusion Criteria:

  • metabolic, chronic and gastro-intestinal disease
  • long-term medication
  • blood donation within 6 month before the study-
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Please refer to this study by its identifier: NCT01483092

Zürich, Switzerland, 8092
Sponsors and Collaborators
Swiss Federal Institute of Technology
Principal Investigator: Richard Hurrell, Prof. Dr. University of Zurich
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Prof. Michael B. Zimmermann, Prof., Swiss Federal Institute of Technology Identifier: NCT01483092     History of Changes
Other Study ID Numbers: INOL
Study First Received: November 9, 2011
Last Updated: June 6, 2013 processed this record on April 21, 2017