Effects of iron supplementation on dominant bacterial groups in the gut, faecal SCFA and gut inflammation: a randomised, placebo-controlled intervention trial in South African children

Br J Nutr. 2014 Aug 28;112(4):547-56. doi: 10.1017/S0007114514001160. Epub 2014 Jun 11.


Fe supplementation is a common strategy to correct Fe-deficiency anaemia in children; however, it may modify the gut microbiota and increase the risk for enteropathogenic infection. In the present study, we studied the impact of Fe supplementation on the abundance of dominant bacterial groups in the gut, faecal SCFA concentration and gut inflammation in children living in rural South Africa. In a randomised, placebo-controlled intervention trial of 38 weeks, 6- to 11-year-old children with Fe deficiency received orally either tablets containing 50 mg Fe as FeSO₄ (n 22) for 4 d/week or identical placebo (n 27). In addition, Fe-sufficient children (n 24) were included as a non-treated reference group. Faecal samples were analysed at baseline and at 2, 12 and 38 weeks to determine the effects of Fe supplementation on ten bacterial groups in the gut (quantitative PCR), faecal SCFA concentration (HPLC) and gut inflammation (faecal calprotectin concentration). At baseline, concentrations of bacterial groups in the gut, faecal SCFA and faecal calprotectin did not differ between Fe-deficient and Fe-sufficient children. Fe supplementation significantly improved Fe status in Fe-deficient children and did not significantly increase faecal calprotectin concentration. Moreover, no significant effect of Fe treatment or time × treatment interaction on the concentrations of bacterial groups in the gut or faecal SCFA was observed compared with the placebo treatment. Also, there were no significant differences observed in the concentrations of any of the bacterial target groups or faecal SCFA at 2, 12 or 38 weeks between the three groups of children when correcting for baseline values. The present study suggests that in African children with a low enteropathogen burden, Fe status and dietary Fe supplementation did not significantly affect the dominant bacterial groups in the gut, faecal SCFA concentration or gut inflammation.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anemia, Iron-Deficiency / diet therapy
  • Anemia, Iron-Deficiency / epidemiology
  • Anemia, Iron-Deficiency / immunology
  • Anemia, Iron-Deficiency / microbiology
  • Child
  • Dietary Supplements / adverse effects*
  • Fatty Acids, Volatile / analysis
  • Fatty Acids, Volatile / metabolism
  • Feces / chemistry
  • Female
  • Ferrous Compounds / administration & dosage
  • Gastroenteritis / chemically induced
  • Gastroenteritis / epidemiology
  • Gastroenteritis / immunology
  • Gastroenteritis / microbiology
  • Gastrointestinal Agents / adverse effects
  • Gastrointestinal Agents / therapeutic use
  • Gram-Negative Bacteria / growth & development*
  • Gram-Negative Bacteria / isolation & purification
  • Gram-Negative Bacteria / metabolism
  • Gram-Positive Bacteria / growth & development*
  • Gram-Positive Bacteria / isolation & purification
  • Gram-Positive Bacteria / metabolism
  • Hematinics / adverse effects*
  • Hematinics / therapeutic use
  • Humans
  • Incidence
  • Intestinal Mucosa / immunology
  • Intestinal Mucosa / metabolism
  • Intestinal Mucosa / microbiology*
  • Iron, Dietary / adverse effects*
  • Iron, Dietary / therapeutic use
  • Leukocyte L1 Antigen Complex / chemistry
  • Leukocyte L1 Antigen Complex / metabolism
  • Lower Gastrointestinal Tract / immunology
  • Lower Gastrointestinal Tract / metabolism
  • Lower Gastrointestinal Tract / microbiology*
  • Male
  • Microbial Viability
  • Rural Health
  • South Africa / epidemiology


  • Fatty Acids, Volatile
  • Ferrous Compounds
  • Gastrointestinal Agents
  • Hematinics
  • Iron, Dietary
  • Leukocyte L1 Antigen Complex
  • ferrous sulfate