Iron deficiency is a global nutritional problem that adversely affects the functional regulation of the immune system. In the process of treatment through iron supplementation, the problem of excessive iron intake often occurs, which increases the level of inflammation in the body. Excessive iron can also lead to an increase in intestinal iron-requiring pathogenic bacteria and an imbalance of intestinal flora. In this study, we aim to explore the effect of Ejiao peptide–iron (EPI) chelates on the intestinal flora and inflammation of ICR mice having iron-deficiency anemia (IDA). The mice were given low, medium, and high doses of EPI and FeSO₄ (1.0, 2.0 and 3.0 mg Fe per kg weight, respectively) daily for 4 weeks by intragastric administration. IDA mice showed increased inflammation levels and decreased sIgA secretion, which were restored after intervention with EPI at different doses. Intestinal mucosal ulcers, inflammatory cell infiltration, and oxidative stress in the colon tissue were reduced, and intestinal permeability was improved. Furthermore, 16S rDNA gene sequencing revealed that EPI increased microbial diversity and richness, changing the community structure, therefore, alleviating microbiota dysbiosis caused by IDA (e.g. the proportion of Firmicutes/Bacteroides). Different from the traditional iron supplement FeSO₄, when the pathogenic bacteria (e.g. Helicobacter and Erysipelatoclostridium) increase and the beneficial bacteria (e.g. Bifidobacterium and Blautia) decrease at high doses, EPI shows higher safety at a high dose, thereby maintaining a healthier intestinal homeostasis.

Food Science of Animal Resources (Food Sci. Anim. Resour.) is an international, peer-reviewed bimonthly journal publishing original research and reviews on basic and applied aspects of the use of animal resources including the meat, egg, dairy, and edible insect/worm products. Food Sci. Anim. Resour. is published and distributed by the Korean Society for Food Science of Animal Resources.

Hepatic lipid accumulation and oxidative stress (OS) lead to non-alcoholic fatty liver disease (NAFLD). Thus, we hypothesized that antihyperlipidemic and antioxidant activities of niga-ichigoside F1 (NI) would ameliorate events leading to NAFLD. Lanbuzheng (Geum japonicum Thunb. var. chinense), a type of wild vegetable found in Southwest China, was used to extract NI. Male C57BL/6J mice were fed a standard diet (Con) or a high-fat diet (HFD) (denoted as diet) with or without 40 mg kg⁻¹ NI (defined as treatment) for 12 weeks. Diet-treatment interactions were observed in the final body weight, fat pad mass, respiratory exchange ratio (RER) in the daytime, and energy expenditure during the whole day. Moreover, NI alleviated hepatic steatosis, possibly by significantly interacting with HFD to regulate lipid metabolism genes (including Srebp1c, Acc1, Fasn, Scd1, Cpt1a and Fabp5). We also found significant diet-treatment interactions on superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) activities, and thiobarbituric acid reactive substance (TBARS) levels, as well as the nuclear and cellular Nrf2 protein levels. Significant free fatty acid (FFA)-treatment interactions on Nrf2 nuclear translocation, antioxidant enzymes activities, genes in lipogenesis (Srebp1c, Acc1, Fasn, and Scd1), and fatty acid oxidation (Pparα) and transport (Fabp5 and Cd36) were also detected in 1 mM FFA-treated HepG2 cells with or without 20 μM NI. These beneficial effects of NI on oxidative stress and lipid accumulation were abolished by Nrf2 siRNA. Our data revealed that dietary NI could prevent HFD-induced hepatic steatosis, possibly via interacting with HFD to activate Nrf2 nuclear translocation to maintain a redox status, thus regulating lipid metabolism genes expressions.