Microalgal nanosized polyphosphate bodies as novel iron supplements for iron-deficiency anemia treatment in rats

Nanosized polyphosphate bodies (PPB) are potential iron supplements for iron deficiency treatment, which can be produced by microalgal cell factories. To investigate the effect of PPB on iron-deficiency anemia, iron-deficient rats were constructed and given feeds with different iron supplements. Four iron supplements, i.e. PPB from microalgae, FeSO4, ferric citrate (FC), and synthetic polyphosphate (PolyP) + FC, were investigated in iron-deficiency anemia treatment at three different dietary intervention stages (i.e. day 3, 7, and 10). These four iron supplements showed similar hemoglobin (Hb) improvements at day 3 and 7, respectively; however, PPB and FeSO4 resulted in higher increased Hb and reticulocyte Hb than FC and PolyP at day 10. The Hb regeneration efficiencies followed the order: PolyP (42.6%) ≈ FC (47.7%) < FeSO4 (56.1%) ≈ PPB (56.2%). The absolute reticulocyte content increased from day 3 to day 7 then decreased at day10 in all iron repletion groups. PPB diet supplied more intestinal total soluble, low-molecular weight, and nanosized iron than FC and PolyP diets. Overall, PPB are novel natural iron supplements that can be used for iron-deficiency anemia treatment, opened new possibilities to develop natural microalgal nanoparticles as high-value products in human health improvement.