Iron-saturated ovotransferrin improved iron deficiency anemia by regulating iron metabolism and remodeling gut microbiota

Iron deficiency anemia (IDA) remains a global nutritional challenge, necessitating effective and safe food-derived iron supplements. This study investigated the ameliorative effect and potential mechanism of iron-saturated ovotransferrin (OVT-Fe) on IDA mice. Results showed that OVT-Fe was significantly better than FeSO₄ in restoring hematological parameters and serum iron metabolism indexes in IDA mice under the same dose intervention. The hemoglobin content (158 ± 5.77 g/L) in H-OVT-Fe was not significantly different from that of normal mice (152.33 ± 7.23 g/L) (P > 0.05). Serum ferritin (SF) and serum iron (SI) levels were elevated by 64.06% and 67.06%, respectively, compared with those in IDA group. Meanwhile, OVT-Fe effectively alleviated the oxidative stress and inflammatory response triggered by IDA, as evidenced by significant increase in liver antioxidant enzymes (SOD, GSH-Px, CAT) activities, a 44.03% reduction in MDA content, and a decrease in pro-inflammatory factors IL-6, TNF-α and C-reactive protein (CRP) by more than 20%. Immunofluorescence and transcriptomics analysis showed that OVT-Fe effectively regulated iron metabolism by down-regulating the expression of duodenal iron transporter (DMT1, Dcytb and FPN), up-regulating the expression of hepcidin in liver, and inhibiting the expression of Tfrc in the hypoxia-inducible factor-1 (HIF-1) signaling pathway. 16S rRNA sequencing revealed that OVT-Fe significantly altered the structure of gut microbiota, showing a decrease in the abundance of potentially pathogenic bacteria such as Mucispirillum and Escherichia-Shigella, and an enrichment of beneficial bacteria such as Muribaculaceae and Bifidobacterium. Pearson correlation analysis confirmed that these bacterial changes were significantly correlated with hematological parameters and SF and SI levels, suggesting that the improvement of intestinal microorganisms played an important role in the mechanism of action of OVT-Fe. In conclusion, OVT-Fe synergistically improved IDA through iron metabolism regulation and gut microbiota remodeling, highlighting its promise as a novel, multifunctional food-derived iron supplement.