Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Switzerland.
Laboratory of Human Nutrition, Institute of Food, Nutrition and Health, ETH Zurich, Switzerland.
Br J Nutr. 2014 Jun 28;111(12):2135-45. doi: 10.1017/S000711451400021X. Epub 2014 Feb 21.
The global prevalence of Fe deficiency is high and a common corrective strategy is oral Fe supplementation, which may affect the commensal gut microbiota and gastrointestinal health. The aim of the present study was to investigate the impact of different dietary Fe concentrations on the gut microbiota and gut health of rats inoculated with human faecal microbiota. Rats (8 weeks old, n 40) were divided into five (n 8 each) groups and fed diets differing only in Fe concentration during an Fe-depletion period (12 weeks) and an Fe-repletion period (4 weeks) as follows: (1) Fe-sufficient diet throughout the study period; (2) Fe-sufficient diet followed by 70 mg Fe/kg diet; (3) Fe-depleted diet throughout the study period; (4) Fe-depleted diet followed by 35 mg Fe/kg diet; (5) Fe-depleted diet followed by 70 mg Fe/kg diet. Faecal and caecal samples were analysed for gut microbiota composition (quantitative PCR and pyrosequencing) and bacterial metabolites (HPLC), and intestinal tissue samples were investigated histologically. Fe depletion did not significantly alter dominant populations of the gut microbiota and did not induce Fe-deficiency anaemia in the studied rats. Provision of the 35 mg Fe/kg diet after feeding an Fe-deficient diet significantly increased the abundance of dominant bacterial groups such as Bacteroides spp. and Clostridium cluster IV members compared with that of an Fe-deficient diet. Fe supplementation increased gut microbial butyrate concentration 6-fold compared with Fe depletion and did not affect histological colitis scores. The present results suggest that Fe supplementation enhances the concentration of beneficial gut microbiota metabolites and thus may contribute to gut health.
全球铁缺乏症的患病率很高，常用的纠正策略是口服补铁，这可能会影响共生肠道微生物群和胃肠道健康。本研究旨在调查不同膳食铁浓度对接种人粪便微生物群大鼠肠道微生物群和肠道健康的影响。将大鼠（8 周龄，n 40）分为五组（每组 8 只），仅在铁耗竭期（12 周）和铁补充期（4 周）期间通过饮食中不同的铁浓度喂养：（1）整个研究期间给予充足铁的饮食；（2）充足铁的饮食后再给予 70mg/kg 饮食的铁；（3）整个研究期间给予缺铁饮食；（4）缺铁饮食后再给予 35mg/kg 饮食的铁；（5）缺铁饮食后再给予 70mg/kg 饮食的铁。分析粪便和盲肠样本的肠道微生物群组成（定量 PCR 和焦磷酸测序）和细菌代谢物（HPLC），并对肠道组织样本进行组织学检查。铁耗竭并未显著改变肠道微生物群的主要种群，也未在研究大鼠中引起缺铁性贫血。与缺铁饮食相比，在给予缺铁饮食后提供 35mg/kg 饮食显著增加了优势细菌群体如拟杆菌属和梭状芽胞杆菌属 IV 群成员的丰度。与铁耗竭相比，铁补充使肠道微生物丁酸浓度增加了 6 倍，但不影响组织学结肠炎评分。本研究结果表明，铁补充增加了有益肠道微生物群代谢物的浓度，从而可能有助于肠道健康。
