Factors affecting iron absorption and the role of fortification in enhancing iron levels.

Iron is an important micronutrient required for a number of biological processes including oxygen transport, cellular respiration, the synthesis of nucleic acids and the activity of key enzymes. The World Health Organization has recognised iron deficiency as the most common nutritional deficiency globally and as a major determinant of anaemia. Iron deficiency anaemia affects 40% of all children between the ages of 6 and 59 months, 37% of mothers who are pregnant and 30% of women between the ages of 15 and 49 years worldwide. Dietary iron exists in two main forms known as haem iron and non-haem iron. Haem iron is obtained from animal sources such as meat and shows higher bioavailability than non-haem iron, which can be obtained from both plant and animal sources. Different components in food can enhance or inhibit iron absorption from the diet. Components such as meat proteins and organic acids increase iron absorption, while phytate, calcium and polyphenols reduce iron absorption. Iron levels in the body are tightly regulated since both iron overload and iron deficiency can exert harmful effects on human health. Iron is stored mainly as haemoglobin and as iron bound to proteins such as ferritin and hemosiderin. Iron deficiency affects individuals at increased risk due to factors such as age, pregnancy, menstruation and various diseases. Different solutions for iron deficiency are applied at individual and community levels. Iron supplements and intravenous iron can be used to treat individuals with iron deficiency, while various types of iron-fortified foods and biofortified crops can be employed for larger communities. Foods such as rice, flour and biscuits have been used to prepare fortified iron products. However, it is important to ensure the fortification process does not exert significant negative effects on organoleptic properties and the shelf life of the food product.

Transcriptome-based nutrigenomics analysis reveals the roles of dietary taurine in the muscle growth of juvenile turbot (Scophthalmus maximus).

The present study explored transcriptomics and gene regulation variations in the muscle of turbot fed with dietary taurine. A 70-day feeding trial was conducted using turbot (initial body weight: 3.66 ± 0.02 g) fed with different levels of dietary taurine: 0 % (C), 0.4 % (T2), 1.2 % (T4) and 2.0 % (T6). Two methods were used to analyze and verify the taurine effects on muscle growth: (1) real-time quantitative PCR (qRT-PCR) for the key muscle growth-related genes and (2) transcriptomic analysis by next-generation sequencing (NGS). The results showed that 1.2 % of dietary taurine supplementation significantly increased the expression of muscle growth stimulatory genes, including TauT, myoD, Myf5, myogenin and follistatin. And also, the 1.2 % level significantly decreased the expression of the muscle growth-restricting gene (myostatin). Meanwhile, transcriptomics analysis found that 1.2 % dietary taurine supplementation significantly increased the number of up-regulated genes linked to metabolic pathways. In contrast, taurine significantly enriched the actin cytoskeleton and metabolic pathways in the T4 and T2 groups, respectively. These findings align with the gene ontology (GO) analysis, which indicated a higher number of cellular component (CC) gene expressions at a 1.2 % of dietary taurine compared to a 0.4 % of dietary taurine supplementation. In conclusion, dietary taurine had positive impacts on the growth-stimulatory genes. Moreover, 1.2 % of dietary taurine supplementation is important to the metabolic pathway enrichment.