Metabolic effect of AOS-iron in rats with iron deficiency anemia using LC-MS/MS based metabolomics.

Iron deficiency anemia (IDA) is a worldwide nutritional problem. The metabolic mechanism of IDA is still unclear. So, the underlying metabolic mechanism of iron supplementation has not been reported even if various iron supplements to treat IDA have been studied. The present study aimed to investigate the metabolic mechanisms of IDA and agar oligosaccharide-iron complex (AOS-iron) supplementation in IDA rats by assessing the changes of endogenous metabolites in serum and liver using LC-MS/MS metabolomics approach. Orthogonal partial least-squares discriminant analysis (OPLS-DA) score plots showed significant separation of metabolites in serum and liver among the normal, anemia model and AOS-iron groups. Seventeen and eight metabolites were identified from serum and liver, respectively. Pathway enrichment analysis suggested that potential biomarkers were strongly involved in the biosynthesis of saturated and unsaturated fatty acids, sphingolipid metabolism, glycerophospholipid metabolism, linoleic acid metabolism, Fcγ receptor (FcγR)-mediated phagocytosis, pancreatic cancer metabolism, regulation of autophagy, gonadotropin releasing hormone (GnRH) signaling pathway, fatty acid metabolism, pantothenate and CoA biosynthesis, glutathione metabolism and primary bile acid biosynthesis. After supplementing 2 mg Fe/kg·bw AOS-iron for 4 weeks, the major metabolites in related pathways disrupted by IDA were restored to normal levels. Therefore, AOS-iron effectively treated IDA by regulating metabolic disorders.

Effectiveness of AOS-iron on iron deficiency anemia in rats.

Iron deficiency anemia (IDA) is one of the most serious nutritional problems. This study aimed to evaluate the therapeutic effects of a novel agar oligosaccharide-iron complex (AOS-iron) on rats with IDA, such as iron supplementation and recovery of antioxidant ability. Eighty-four weaned male SD rats were randomly divided into a normal control group (n = 12), which was fed with a standard diet, and an anemia model group (n = 72), which was fed with an iron-deficient diet for 4 weeks to establish a model of IDA. After the model was established, the rats with IDA were divided into six groups, namely, an anemia model group, a ferrous gluconate group, a ferrous sulfate (FeSO4) group, and low-dose (LD), medium-dose (MD) and high-dose (HD) AOS-iron groups, and fed with an iron-deficient diet and different iron supplements for 4 weeks, respectively. The results showed that HD AOS-iron exerted a significant restorative effect by returning blood parameters to normal levels in rats with IDA, including hemoglobin, red blood cells, hematocrit, mean cell volume, mean cell hematocrit, mean cell hemoglobin concentration, serum iron, total iron binding capacity, transferrin saturation, and serum ferritin. A histological analysis suggested that the liver morphology in the MD and HD AOS-iron groups was similar to that in the normal group. Furthermore, MD and HD AOS-iron improved antioxidant activities in the serum and liver. In general, high-dose (the same dose as those of ferrous gluconate and FeSO4) AOS-iron exhibited the best effects in terms of iron supplementation and antioxidant activities. The present findings showed that AOS-iron might be a potential new iron supplement.

Prebiotic effects of resistant starch from purple yam (Dioscorea alata L.) on the tolerance and proliferation ability of Bifidobacterium adolescentis in vitro.

The in vitro prebiotic effects of resistant starch (RS), prepared by different treatments from purple yam, on Bifidobacterium adolescentis (bifidobacteria for short), were investigated. Tolerance tests indicated that bifidobacteria in PDS (prepared by debranching combined with autoclaving) and PDS.H (PDS further treated by double enzyme hydrolysis) media adapted better to simulated upper gastrointestinal conditions (at pH 1.5-3.0 and 0.3% and 1.0% bile acid) than those in GLU (glucose) and DAS (prepared by autoclaving) media. PDS.H, which had the highest digestion resistibility, exhibited significant effects on the OD600 nm value (1.544) and the pH value (4.21) when the carbohydrate concentration was 20 g L-1. Additionally, the exponential growth phase of bifidobacteria was 2 h in the PDS or PDS.H media, whereas it was 4 h in the GLU or DAS media. A higher content of short-chain fatty acids (SCFAs) was obtained in the PDS.H medium. Analysis of the structural features of RS and fermented RS indicated that PDS, especially PDS.H, had a rougher surface and higher crystallinity than DAS. Fermented RS in a simulated large bowel environment showed an eroded surface and decreased crystallinity. All of these findings suggest that RS with a rough surface and perfect crystalline structure could protect bifidobacteria from gastrointestinal conditions and enhance the proliferation of bifidobacteria.