Dysregulation of the CD163-Haptoglobin Axis in the Airways of COPD Patients

Pulmonary iron levels are increased in chronic obstructive pulmonary disease (COPD) patients. Iron causes oxidative stress and is a nutrient for pathogenic bacteria. Iron may therefore play an important role in the pathophysiology of COPD. The CD163-haptglobin axis plays a central role in the regulation of iron bioavailability. The aim of this study was to examine dysregulation of the CD163-haptglobin axis in COPD. We measured soluble CD163 (sCD163) and haptoglobin levels in sputum supernatants by enzyme-linked immunosorbent assay (ELISA) and sputum macrophage CD163 and haptoglobin expression by flow cytometry in COPD patients and controls. SCD163 levels were lower in COPD patients compared to controls (p = 0.02), with a significant correlation to forced expiratory volume in 1 s (FEV1)% predicted (rho = 0.5, p = 0.0007). Sputum macrophage CD163 expression was similar between COPD patients and controls. SCD163 levels and macrophage CD163 expression were lower in COPD current smokers compared to COPD ex-smokers. Haptoglobin levels were not altered in COPD patients but were regulated by genotype. Macrophage CD163 and haptolgobin expression were significantly correlated, supporting the role of CD163 in the cellular uptake of haptoglobin. Our data implicates a dysfunctional CD163-haptoglobin axis in COPD, which may contribute to disease pathophysiology, presumably due to reduced clearance of extracellular iron.

Sensory Characteristics and Nutritional Quality of Food Products Made with a Biofortified and Lectin Free Common Bean (Phaseolus vulgaris L.) Flour

Common beans (Phaseolus vulgaris L.) are an important source of nutrients with beneficial effects on human health. However, they contain lectins, that limit the direct use of flour in food preparations without thermal treatment, and phytic acid, that reduces mineral cation bioavailability. The objectives of this research were: to obtain biofortified snacks and a cream using an untreated common bean flour devoid of active lectins (lec−) and with reduced content of phytic acid (lpa) and to evaluate the sensorial appreciation for these products. The main results of the present work were: the products with the lpa lec− flour did not retain residual hemagglutinating activity due to lectins; they showed higher residual α-amylase inhibitor activity (from 2.2 to 135 times), reduced in vitro predicted glycemic index (about 5 units reduction) and increased iron bioavailability compared to the products with wild type flour; products with common bean flour were less appreciated than the reference ones without this flour, but the presence of an intense umami taste can be a positive attribute. Results confirmed that the use of the lpa lec− flour has important advantages in the preparation of safe and nutritionally improved products, and provide useful information to identify target consumers, such as children and elderly people.

Dietary Iron

Iron metabolism differs from the metabolism of other metals in that there is no physiologic mechanism for iron excretion, it is unusual; approximately 90% of daily iron needs are obtained from an endogenous source, the breakdown of circulating RBCs. Additionally humans derive iron from their everyday diet, predominantly from plant foods and the rest from foods of animal origin. Iron is found in food as either haem or non-haem iron. Iron bioavailability has been estimated to be in the range of 14–18% for mixed diets and 5–12% for vegetarian diets in subjects with no iron stores. Iron absorption in humans is dependent on physiological requirements, but may be restricted by the quantity and availability of iron in the diet. Bioavailability of food iron is strongly influenced by enhancers and inhibitors in the diet. Iron absorption can vary from 1 to 40%. A range of iron bioavailability factors that depend on the consumption of meat, fruit, vegetables, processed foods, iron-fortified foods, and the prevalence of obesity. The methods of food preparation and processing influence the bioavailability of iron. Cooking, fermentation, or germination can, by thermal or enzymatic action, reduce the phytic acid and the hexa- and penta-inositol phosphate content. Thus improving bioavailability of non-haem iron. This chapter will elaborate the dietary iron sources and means of enhancing bioavailability.

Temporal variation of planetary iron as a driver of evolution

Iron is an irreplaceable component of proteins and enzyme systems required for life. This need for iron is a well-characterized evolutionary mechanism for genetic selection. However, there is limited consideration of how iron bioavailability, initially determined by planetary accretion but fluctuating considerably at global scale over geological time frames, has shaped the biosphere. We describe influences of iron on planetary habitability from formation events >4 Gya and initiation of biochemistry from geochemistry through oxygenation of the atmosphere to current host–pathogen dynamics. By determining the iron and transition element distribution within the terrestrial planets, planetary core formation is a constraint on both the crustal composition and the longevity of surface water, hence a planet’s habitability. As such, stellar compositions, combined with metallic core-mass fraction, may be an observable characteristic of exoplanets that relates to their ability to support life. On Earth, the stepwise rise of atmospheric oxygen effectively removed gigatons of soluble ferrous iron from habitats, generating evolutionary pressures. Phagocytic, infectious, and symbiotic behaviors, dating from around the Great Oxygenation Event, refocused iron acquisition onto biotic sources, while eukaryotic multicellularity allows iron recycling within an organism. These developments allow life to more efficiently utilize a scarce but vital nutrient. Initiation of terrestrial life benefitted from the biochemical properties of abundant mantle/crustal iron, but the subsequent loss of iron bioavailability may have been an equally important driver of compensatory diversity. This latter concept may have relevance for the predicted future increase in iron deficiency across the food chain caused by elevated atmospheric CO2.

GENERIC ALGORITHM SOLUTION IN ESTIMATION OF THE IRON ABSORPTION POTENTIAL FROM COMPLEX SCHOOL MEALS

New analytical tools to study iron bioavailability are proposed in this article. An algorithm was devised to predict dietary iron abortion from school meals based on the contents of dietary factors that have the ability to promote or inhibit heme or non-heme iron absorption. The highest absorption rate of iron from representative meals was observed in the presence of ascorbic acid (27,73%) or meat ingredients (27,70%), and the lowest absorption rate – in the presence of Ca (12,40%), tannins (5,83%) and polyphenols (5,36%). Relationships between quantities of total iron intake from foods (dialyzable iron, in vitro assay) and the value of nutritional factors in those are described as exponential equations allowing calculations at any stationary state. In elaborated formula the rate of iron absorbance can be predicted considering one, two or three nutritional factors at the same time. The results emphasize the fact that it is important to understand the meal composition for the correct estimation of iron bioavailability.

A Narrative Review: In-vitro Methods for Assessing Bio-Accessibility/Bioavailability of Iron in Plant-Based Foods

In-vitro measurement has the advantage of rapid and convenient method of screening the iron bioavailability within the range of plant-based foods. It is important to do preliminary screening as it provides information which will be useful to identify promising plant sources of iron before moving to human trials. A review on in-vitro methods of bio-accessibility and bioavailability of iron in plant-based foods including fruits, vegetables, cereals and legumes is entailed here. The review will focus on in-vitro methods of iron bioavailability in plant-based foods and the effects of inhibitors and processing on the iron bioavailability. The variation of the methods and updates on a recent INFOGEST method used to measure the bioavailability of iron in plant-based foods will also be discussed.

Dietary Iron Consumption Estimates Among Women Of Reproductive Age In Kersa, Eastern Ethiopia: Cross-Sectional Study

Dietary iron inadequacy is a public health concern in developing countries. Women of reproductive age (WRA) are the most at risk for this micronutrient deficiency due to biological, socio-cultural, and dietary factors. This analysis aimed to assess estimated dietary intakes of iron (including heme and non-heme) and estimate bioavailability of dietary iron intake in Ethiopian women of reproductive age in Kersa district, Eastern Ethiopia. A total of 1140 randomly selected women from households in Kersa participated in this study. We used a non-quantitative food frequency questionnaire to assess total dietary iron consumption in WRA. Adjusted prevalence ratios (APRs) and 95% confidence intervals (CIs) were computed using modified Poisson regression to evaluate factors for inadequate dietary iron intake. The median usual iron consumption was 24.7 mg/d and 41.8 % of WRA were at risk for iron inadequacy. The following factors were associated with a greater likelihood for the risk of iron inadequacy: seasonal (APR 1.56; 95% CI 1.36-1.80) and part-time (APR 1.75; 95% CI 1.45-2.12) agricultural employment, market food source (APR 1.30; 95% CI 1.14-1.49), old age (APR 1.29; 95% CI 1.05-1.60) and low women’s dietary diversity (APR 2.34; 95% CI 1.88-2.91). Two-fifths of women had an inadequate dietary iron intake. Improving dietary diversity and food security, fortifying staple foods that have low iron bioavailability, and increasing animal-based foods and fruit consumption with meals would help to decrease the burden of iron dietary inadequacy and deficiency in WRA.

Iron Bioavailability from Multiple Biofortified Foods Using an In Vitro Digestion, Caco-2 Assay for Optimizing a Cyclical Menu for a Randomized Efficacy Trial

ABSTRACT Background Inadequate nutritional status contributes to substantial losses in human health and productivity globally. A multiple biofortified food crop trial targeting iron, zinc, and vitamin A deficiencies among young children and their breastfeeding mothers is being conducted in India. Objective We sought to determine the relative iron bioavailability from biofortified and conventional crops and crop combinations representative of a cyclical menu using crops targeted for inclusion in the feeding trial. Methods Crops were procured from India, cooked, freeze-dried, and analyzed with an established in vitro digestion/Caco-2 iron bioavailability assay using a fixed sample weight. Crop proportions representative of meals planned for the human study were determined and combined such that samples included either all biofortified or all control crops. Crops were analyzed as single crops (n = 4) or crop combinations (n = 7) by variety (biofortified or control) in triplicate. The primary outcome was iron uptake measured by Caco-2 ferritin production normalized to total Caco-2 protein (nanograms of ferritin/milligrams of cell protein) analyzed for effects of crop variety and crop proportion using generalized linear models. Results Biofortified pearl millet alone demonstrated higher iron uptake than conventional varieties (5.01 ± 1.66 vs. 2.17 ± 0.96; P = 0.036). Addition of sweet potato or sweet potato + pulse improved iron uptake for all proportions tested in control varieties and select proportions for biofortified varieties (P ≤ 0.05). Two multiple crop combinations demonstrated modestly higher iron uptake from biofortified crops. Conclusions Optimizing total iron delivery should consider matrix effects, processing, and promoters/inhibitors of iron absorption in addition to total iron concentration. Future directions include evaluating recipes as prepared for consumption and comparison against human iron bioavailability studies.