Intestinal iron bio-accessibility changes by Lignin and the subsequent impact on cell metabolism and intestinal microbiome communities
Open Access
- 21 March 2023
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Food & Function
- Vol. 14 (8), 3673-3685
- https://doi.org/10.1039/d2fo03807b
Abstract
The detrimental effects of high concentrations of colonic iron have been linked to intestinal inflammation and microbial dysbiosis. Exploiting chelation against this luminal pool of iron may restore intestinal health and have beneficial impacts on microbial communities. This study aimed to explore whether lignin, a heterogenous polyphenolic dietary component, has iron-binding affinity and can sequester iron within the intestine and thus, potentially modulate the microbiome. Within in vitro cell-culture models, the treatment of RKO and Caco-2 cells with lignin almost abolished intracellular iron import (96 % and 99 % reduction of iron acquisition respectively) with corresponding changes in iron metabolism proteins (ferritin and transferrin receptor-1) and reductions in the labile-iron pool. In a Fe-59 supplemented murine model, intestinal iron absorption was significantly inhibited by 30 % when lignin was co-administered compared to the control group with the residual iron lost in the faeces. The supplementation of lignin into a microbial bioreactor colonic model increased the solubilisation and bio-accessibility of iron present by 4.5-fold despite lignin-iron chelation previously restricting intracellular iron absorption in vitro and in vivo. The supplementation of lignin in the model increased the relative abundance of Bacteroides whilst levels of Proteobacteria decreased which could be attributed to the changes in iron bio-accessibility due to iron chelation. In summary, we demonstrate that lignin is an effective luminal iron chelator. Iron chelation leads to the limitation of intracellular iron import whilst, despite increasing iron solubility, favours the growth of beneficial bacteria.Keywords
Funding Information
- Biotechnology and Biological Sciences Research Council (BB/R00773X/1)
This publication has 45 references indexed in Scilit:
- An improved Greengenes taxonomy with explicit ranks for ecological and evolutionary analyses of bacteria and archaeaThe ISME Journal, 2011
- RNA-Seq methods for imperfect samples: development, evaluation and applicationsGenome Biology, 2011
- Dietary fibre in foods: a reviewJournal of Food Science and Technology, 2011
- Metagenomic biomarker discovery and explanationGenome Biology, 2011
- Depletion of luminal iron alters the gut microbiota and prevents Crohn's disease-like ileitisGut, 2010
- Intravenous iron sucrose is superior to oral iron sulphate for correcting anaemia and restoring iron stores in IBD patients: A randomized, controlled, evaluator-blind, multicentre studyScandinavian Journal of Gastroenterology, 2009
- Purified lignin: Nutritional and health impacts on farm animals—A reviewAnimal Feed Science and Technology, 2008
- UniFrac: a New Phylogenetic Method for Comparing Microbial CommunitiesApplied and Environmental Microbiology, 2005
- Conservation evaluation and phylogenetic diversityBiological Conservation, 1992
- Binding of Iron by Cellulose, Lignin, Sodium Phytate and Beta-Glucan, Alone and in Combination, Under Simulated Gastrointestinal pH ConditionsJournal of Food Science, 1984