Department of Food Sciences and Human Nutrition, Iowa State University, Ames, IA, USA.
ETH Zürich, Institute of Food, Nutrition, and Health, Zurich, Switzerland.
J Nutr. 2020 May 1;150(5):1109-1115. doi: 10.1093/jn/nxaa035.
Bouillon cubes are a potential vehicle for iron fortification. They are currently fortified with ferric pyrophosphate (FePP), which is known to be poorly absorbed. The objective of this study was to assess the iron absorption of Aspergillus oryzae grown in FePP (ASP-p) and compare it with FePP and ferrous sulfate (FeSO4)-fortified bouillon cubes.
In 2 single-blinded, crossover studies, healthy women with serum ferritin concentrations <40 μg/L were randomly assigned to consume a rice-vegetable meal with iron-fortified chicken bouillon. Subjects in study I (n = 17, 18-26 y) consumed iron from both iron sources as 57FePP and 58ASP-p (intrinsically labeled with 58FePP) with a meal containing 4.2 mg of total iron provided for 3 d. Study II (n = 18, 18-29 y) was similar except that subjects consumed 57FeSO4 and 58ASP-p. Whole-blood stable isotope enrichment after 14 d was used to measure fractional iron absorption. Hemoglobin, hematocrit, serum ferritin, hepcidin, and serum C-reactive protein were analyzed at baseline and at 14 d. A t test was used to compare the mean differences in fractional absorptions within each study and baseline characteristics between studies.
Geometric mean (95% CI) fractional iron absorption of FePP [0.94% (0.63%, 1.40%)] was lower than ASP-p [2.20% (1.47%, 3.30%)] (P < 0.0001) in study I. In study II, ASP-p fractional absorption [2.98% (2.03%, 4.38%)] was lower than that of FeSO4 [9.88% (6.70%, 14.59%)] (P < 0.0001). Both ferritin (r = -0.41, P = 0.014) and hepcidin (r = -0.42, P = 0.01) concentrations were inversely correlated with ASP-p iron absorption. Fractional absorption of ASP-p was also positively correlated with FePP (r = 0.92, P < 0.0001) and FeSO4 (r = 0.52, P < 0.02) absorption.
ASP-p-fortified bouillon provided 2.3-fold higher absorbable iron than the currently used FePP. Bouillon fortified with ASP-p may contribute sufficient bioavailable iron to meet the daily iron requirements in young women only if consumed with other iron-fortified staple foods. This trial was registered at clinicaltrials.gov as NCT03586245.
肉汁晶块是一种潜在的铁强化载体。目前，它们是用焦磷酸铁（FePP）来强化的，已知其吸收率较低。本研究的目的是评估在 FePP 中生长的米曲霉（Aspergillus oryzae）（ASP-p）的铁吸收率，并将其与 FePP 和硫酸亚铁（FeSO4）强化肉汁晶块进行比较。
在 2 项单盲、交叉研究中，血清铁蛋白浓度＜40μg/L 的健康女性被随机分配食用铁强化鸡肉肉汁的米饭-蔬菜餐。研究 I（n=17，18-26 岁）的参与者摄入 57FePP 和 58ASP-p（用 58FePP 进行内标）作为两种铁源，每餐提供 4.2mg 的总铁，持续 3 天。研究 II（n=18，18-29 岁）类似，但参与者摄入 57FeSO4 和 58ASP-p。14 天后，全血稳定同位素丰度用于测量铁的分数吸收。在基线和第 14 天分析血红蛋白、红细胞压积、血清铁蛋白、hepcidin 和血清 C 反应蛋白。在每项研究中，使用 t 检验比较吸收分数的均值差异，并比较研究之间的基线特征。
研究 I 中，FePP[0.94%（0.63%，1.40%）]的铁分数吸收率低于 ASP-p[2.20%（1.47%，3.30%）]（P＜0.0001）。在研究 II 中，ASP-p 的铁分数吸收率[2.98%（2.03%，4.38%）]低于 FeSO4[9.88%（6.70%，14.59%）]（P＜0.0001）。血清铁蛋白（r=-0.41，P=0.014）和 hepcidin（r=-0.42，P=0.01）浓度与 ASP-p 铁吸收呈负相关。ASP-p 的铁吸收分数也与 FePP（r=0.92，P＜0.0001）和 FeSO4（r=0.52，P＜0.02）的吸收呈正相关。
与目前使用的 FePP 相比，ASP-p 强化肉汁晶块提供了 2.3 倍更高的可吸收铁。如果与其他强化主食一起食用，富含 ASP-p 的肉汁晶块可能会提供足够的生物可利用铁，以满足年轻女性的日常铁需求。本研究在 clinicaltrials.gov 上注册为 NCT03586245。
