Effect of ferrous sulfate on intestinal health of mice with iron deficiency anemia

Abstract:

[Objective] To explore the effect of ferrous sulfate (FeSO₄) on the intestinal health of iron deficiency anemia (IDA) mice. [Methods] A total of 45 24-day-old male Kunming mice with initial body weight of (16.0±1.2) g were randomized into 3 groups (15 in each): control group (normal diet, distilled water), IDA group (low-iron diet for 2 weeks for modeling, deionized water), and IDA-Fe²⁺ group (after modeling, gavage with FeSO₄ for 3 weeks, deionized water). Sampling performed at the end of the experiment. [Results] Anemia indexes of mice in IDA-Fe²⁺ group, such as erythrocyte, hemoglobin, hematocrit, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC), returned to normal levels compared with those in the IDA group (P>0.05), indicating that FeSO₄ can alleviate IDA. Compared with the control group, IDA and IDA-Fe²⁺ groups had high levels of oxidative stress indexes and tumor necrosis factor α (P<0.01) and low level of Occludin (P<0.001). The indexes, except for the total antioxidant capacity (TAC), were insignificantly different between the IDA-Fe²⁺ and IDA groups (P>0.05). As for the hematoxylin and eosin (HE) staining results of colon tissue, the IDA group showed atrophy of colonic mucosa, defective arrangement of epithelial cells in mucosa, and atrophy of lamina propria. After intragastric administration of FeSO₄ for 3 weeks, IDA-Fe²⁺ group still demontrated defective arrangement of epithelial cells in the mucosa, necrotic and defective acini of mucosa, and atrophy of lamina propria. According to the results of Illumina MiSeq high-throughput sequencing of fecal microbiota, IDA could lead to the disorder of intestinal microflora and the variation of diversity indexes (Shannon, Chao1, Ace, and Simpson indexes) of intestinal flora (P<0.05). IDA-Fe²⁺ group showed significant increase in diversity indexes of the flora and improvement of the overall structure of intestinal flora as compared with the IDA group (P<0.05). To be specific, at the phylum level, the abudance of Bacteroidetes decreased (P<0.05) and that of Verrucomicrobia increased (P<0.01), both returning to the normal levels. At the genus level, the abundance of the dominant genera changed. The abundance of the beneficial Akkermansia and Coprobacter increased (P<0.05) and that of the pathogenic Parabacteroides decreased (P<0.01). [Conclusion] FeSO₄ can alleviate IDA symptoms by improving the blood indexes, but failes to improve the oxidative stress indexes, inflammation indexes, and colon tissue pathological changes of IDA mice. However, FeSO₄ can increase the diversity of intestinal flora and the abundance of main dominant flora in IDA mice, raising the abundance of beneficial bacteria and reducing the abundance of pathogenic bacteria.