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Background/Objectives: Fortifying cereal staples with zinc is a strategy for increasing zinc intake in young children in developing countries. However, phytic acid (PA) naturally present in cereals strongly decreases zinc absorption. A stable-isotope zinc absorption study was conducted in young children to investigate the ability of the PA-degrading enzyme phytase to improve zinc absorption, when added to a cereal porridge immediately before consumption. Subjects/Methods: Fractional absorption of zinc (FAZ) was estimated in 35 young healthy Burkinabe children using the double-isotopic tracer ratio method with 67 Zn as oral tracer and 70 Zn as intravenous tracer, in a crossover design. The test meals were: (a) a millet-based porridge containing 1.4 mg total zinc (native plus 1 mg added as ZnSO 4 ) with a PA:Zn molar ratio of 7.7; (b) the same porridge with the enzyme phytase (20.5 phytase units (FTU)) added immediately before consumption. The exchangeable zinc pool (EZP) was determined as a potential measure of long-term zinc intake in 20 of the 35 children and compared with FAZ. Results: Mean FAZ increased from 9.5±3.4 to 16.0±5.1% ( P <0.0001), when phytase was added to the meal. The mean EZP was 3.6±0.5 mg/kg. There was no correlation between the EZP and FAZ values for either of the two test meals. Conclusions: Adding phytase immediately prior to consumption of a zinc-fortified cereal-based complementary food can improve zinc absorption in young children.

Zinc absorption in the small intestine is one of the main mechanisms regulating the systemic homeostasis of this essential trace element. This review summarizes the key aspects of human zinc homeostasis and distribution. In particular, current knowledge on human intestinal zinc absorption and the influence of diet-derived factors on bioaccessibility and bioavailability as well as intrinsic luminal and basolateral factors with an impact on zinc uptake are discussed. Their investigation is increasingly performed using in vitro cellular intestinal models, which are continually being refined and keep gaining importance for studying zinc uptake and transport via the human intestinal epithelium. The vast majority of these models is based on the human intestinal cell line Caco-2 in combination with other relevant components of the intestinal epithelium, such as mucin-secreting goblet cells and in vitro digestion models, and applying improved compositions of apical and basolateral media to mimic the in vivo situation as closely as possible. Particular emphasis is placed on summarizing previous applications as well as key results of these models, comparing their results to data obtained in humans, and discussing their advantages and limitations.

Background: Phytic acid is abundant in plant-based diets and acts as a micronutrient inhibitor for humans and non-ruminant animals. Phytases are enzymes that break down phytic acid, releasing micronutrients and enhancing their bioavailability, particularly iron and zinc. Deficiencies in iron and zinc are significant public health problems, especially among populations with disease-associated malnutrition or those in developing countries consuming phytic acid-rich diets. This narrative review aimed to summarize findings from human intervention studies on the interactions between phytic acid, phytase, and micronutrient bioavailability. Methods: An extensive PubMed search (1 January 1990 to 8 February 2024) was conducted using MeSH terms (phytic acid, phytase, IP6, “inositol hexaphosphate,” micronutrient, magnesium, calcium, iron, zinc). Eligible studies included human intervention trials investigating the bioavailability of micronutrients following (a) phytase supplementation, (b) consumption of phytic acid-rich foods, or (c) consumption of dephytinized foods. In vitro, animal, cross-sectional, and non-English studies were excluded. Results: 3055 articles were identified. After the title and full-text review, 40 articles were eligible. Another 2 were identified after cross-checking reference lists from included papers, resulting in 42 included articles. Most studies exploring the efficacy of exogenous phytase (9 of 11, 82%) or the efficacy of food dephytinization (11 of 14, 79%) demonstrated augmented iron and zinc bioavailability. Most phytic acid-rich food-feeding studies (13 of 17, 77%) showed compromised iron and zinc bioavailability. Conclusions: Strong evidence supports decreased iron and zinc bioavailability in phytic acid-rich diets and significant improvements with phytase interventions. Studies of longer periods and within larger populations are needed.

Background Deficiencies of iron and folic acid during pregnancy can lead to adverse outcomes for the fetus, thus supplements are recommended. Adherence to current tablet-based supplements is documented to be poor. Recently a powdered form of micronutrients has been developed which may decrease side-effects and thus improve adherence. However, before testing the efficacy of the supplement as an alternate choice for supplementation during pregnancy, the bioavailability of the iron needs to be determined. Our objective was to measure the relative bioavailability of iron and folic acid from a powdered supplement that can be sprinkled on semi-solid foods or beverages versus a traditional tablet supplement in pregnant women. Methods Eighteen healthy pregnant women (24 – 32 weeks gestation) were randomized to receive the supplements in a crossover design. Following ingestion of each supplement, the changes (over baseline) in serum iron and folate over 8 hours were determined. The powdered supplement contained 30 mg of iron as micronized dispersible ferric pyrophosphate with an emulsifier coating and 600 μg folic acid; the tablet contained 27 mg iron from ferrous fumarate and 1000 μg folic acid. Results Overall absorption of iron from the powdered supplement was significantly lower than the tablet (p = 0.003). There was no difference in the overall absorption of folic acid between supplements. Based on the differences in the area under the curve and doses, the relative bioavailability of iron from powdered supplement was lower than from the tablet (0.22). Conclusion The unexpected lower bioavailability of iron from the powdered supplement is contrary to previously published reports. However, since pills and capsules are known to be poorly accepted by some women during pregnancy, it is reasonable to continue to explore alternative micronutrient delivery systems and forms of iron for this purpose. Trial Registration ClinicalTrials.gov NCT00789490

Diets high in wholegrains are associated with a 20-30% reduction in risk of developing type-2 diabetes (T2D), which is attributed to a variety of wholegrain components, notably dietary fibre, vitamins, minerals and phytochemicals. Most phytochemicals function as antioxidants in vitro and have the potential to mitigate oxidative stress and inflammation which are implicated in the pathogenesis of T2D. In this review we compare the content and bioavailability of phytochemicals in wheat, barley, rice, rye and oat varieties and critically evaluate the evidence for wholegrain cereals and cereal fractions increasing plasma phytochemical concentrations and reducing oxidative stress and inflammation in humans. Phytochemical content varies considerably within and among the major cereal varieties. Differences in genetics and agro-climatic conditions explain much of the variation. For a number of the major phytochemicals, such as phenolics and flavanoids, their content in grains may be high but because these compounds are tightly bound to the cell wall matrix, their bioavailability is often limited. Clinical trials show that postprandial plasma phenolic concentrations are increased after consumption of wholegrain wheat or wheat bran however the magnitude of the response is usually modest and transient. Whether this is sufficient to bolster antioxidant defences and translates into improved health outcomes is still uncertain. Increased phytochemical bioavailability may be achieved through bio-processing of grains but the improvements so far are small and have not yet led to changes in clinical or physiological markers associated with reduced risk of T2D. Furthermore, the effect of wholegrain cereals and cereal fractions on biomarkers of oxidative stress or strengthening antioxidant defence in healthy individuals is generally small or nonexistent, whereas biomarkers of systemic inflammation tend to be reduced in people consuming high intakes of wholegrains. Future dietary intervention studies seeking to establish a direct role of phytochemicals in mediating the metabolic health benefits of wholegrains, and their potential for mitigating disease progression, should consider using varieties that deliver the highest possible levels of bioavailable phytochemicals in the context of whole foods and diets. Both postprandial and prolonged responses in systemic phytochemical concentrations and markers of inflammation and oxidative stress should be assessed along with changes related to health outcomes in healthy individuals as well as those with metabolic disease.

Chronic kidney disease (CKD) predisposes one to either deficiency or toxic excess of different micronutrients. The knowledge on micronutrients—specifically water-soluble vitamins and trace elements—in CKD is very limited. Consequently, current guidelines and recommendations are mostly based on expert opinions or poor-quality evidence. Abnormalities of micronutrient resources in CKD develop for several reasons. Dietary restrictions and anorexia lead to an insufficient micronutrient intake, while diuretics use and renal replacement therapy lead to their excessive losses. Absorption is unpredictable, and metabolism impaired. Better understanding of the micronutrient needs of CKD patients could have an impact on many complications linked to vitamin and trace element disorders, including high mortality, increased risk of atherosclerosis, inflammation, oxidative stress, anemia, polyneuropathy, encephalopathy, weakness and fragility, muscle cramps, bone disease, depression, or insomnia. Here, we summarize the up-to-date knowledge on micronutrient resources in different stages of CKD, and share our experience with the assessment of micronutrient status.

Si/SiO x nanoparticles (NPs) produced by laser ablation in deionized water or aqueous biocompatible solutions present a novel extremely promising object for biomedical applications, but the interaction of these NPs with biological systems has not yet been systematically examined. Here, we present the first comprehensive study of biodistribution, biodegradability and toxicity of laser-synthesized Si-SiO x nanoparticles using a small animal model. Despite a relatively high dose of Si-NPs (20 mg/kg) administered intravenously in mice, all controlled parameters (serum, enzymatic, histological etc.) were found to be within safe limits 3 h, 24 h, 48 h and 7 days after the administration. We also determined that the nanoparticles are rapidly sequestered by the liver and spleen, then further biodegraded and directly eliminated in urine without any toxicity effects. Finally, we found that intracellular accumulation of Si-NPs does not induce any oxidative stress damage. Our results evidence a huge potential in using these safe and biodegradable NPs in biomedical applications, in particular as vectors, contrast agents and sensitizers in cancer therapy and diagnostics (theranostics).

Background/Objectives: Zinc, an important trace metal, requires daily intake but dietary antagonists including phytic acid reduce its absorption. It is unclear if phytic acid affects zinc absorption at the level of bioaccessibility (how much soluble zinc is available from digestion) or bioavailability (how much zinc is absorbed by the intestine). This study investigates at which level this occurs at and if the zinc source alters the response. Methods: Following a standardised in vitro digestion (INFOGEST), the yield of soluble zinc was measured as the bioaccessible fraction from inorganic and chelated zinc sources, with and without phytic acid. Bioavailability was assessed by measuring cellular zinc uptake in intestinal cell lines (Caco-2 and IPEC-J2). Results: Phytic acid affected the bioaccessibility of zinc, with varying impacts depending on the zinc source. Zinc proteinate had the highest bioaccessibility (42%) without phytic acid, while inorganic zinc sulphate (24%) and zinc bisglycinate (27%) were lower. ZnSO4 was more susceptible to phytic acid antagonism than chelated zinc sources (from 2:100 molar ratio of phytic acid: zinc), while the chelated zinc sources were only affected at a molar ratio of 4:100, with zinc bisglycinate being more susceptible than zinc proteinate. Cellular zinc uptake (bioavailability) and toxicity at equimolar concentrations were unaffected by phytic acid. Conclusions: This study found that phytic acid affected bioaccessibility, not bioavailability. The zinc source impacts the response. Zinc proteinate was consistently more bioaccessible while both chelated zinc sources were less susceptible to phytic acid than inorganic zinc.

Nano-technology is an emerging technology with tremendous potential and diverse applications in human health, agriculture, and animal nutrition. It also offers potential advantages in supporting research in many areas of life sciences. Nano-technology has many vital biological applications as living systems depend on many nano-scale objects like proteins, DNA, and enzymes. Trace minerals are normally used in very minute quantity in animal nutrition but issues like lower bioavailability, antagonism, and higher excretion rates from body limit their efficiency. Nano-technology offers opportunity to mediate these issues as nano-particles possess different physical and chemical properties than other forms of minerals. Nano-particles possess higher physical activity and chemical neutrality. Bioavailability can be enhanced by increasing the surface area of respective minerals by making their nano-particles. Owing to potential advantages of nano-particles, interest in exploring their potential use and efficacy in animal production has increased significantly in this decade. Although limited literature is available regarding potential effects of nano-particles in poultry nutrition, still some convincing evidences have suggested the feeding of trace minerals (zinc, copper, silver, selenium, iron, chromium, and manganese) in the diets of broilers, layers, turkeys, quails, etc. Excellent antimicrobial activities of nano-particles of Ag, Cu, and Zn, against key poultry pathogens like Salmonella and Campylobacter, indicate their potential for effective use in poultry production. Recent studies have also demonstrated modulation of gut health by nano-particle through increasing abundance of beneficial microbes ( Lactobacillus and Faecalibacterium ) and production of short-chain fatty acids. This review aims to provide insights on absorption, metabolism, and distribution of nano-minerals in the body. Moreover, potential applications and various aspects of using nano-trace minerals in different poultry species with potential effects on performance and health of birds are discussed.

We evaluated the influence of intestinal malabsorption on iodine status in patients who had short gut syndrome and received total parenteral nutrition (group I) compared with control subjects who had eutrophia (group II) and patients who had other illnesses but normal digestive tracts (group III). Twenty-seven subjects were studied. Iodine intake was determined by the measurement of iodine in ingested food and in parenteral nutrition solutions. Urinary iodine excretion was measured by the Sandell-Kalthoff reaction. Urinary creatinine, anthropometric, and thyroid hormone functions were also determined. Daily iodine intakes were 658 ± 125 (mean ± standard deviation), 573 ± 204, and 629 ± 208 μg for groups I, II, and III, respectively. Daily urinary iodine excretion levels were 399 ± 308, 439 ± 192, and 370 ± 268 μg and ratios of urinary iodine (micrograms) to creatinine (grams) were 614 ± 349, 354 ± 142, and 483 ± 292, respectively. There were no statistically significant differences across groups. In Brazil the iodine provided by food, including iodized salt, has been sufficient to maintain iodine status in patients with short gut syndrome.