The Impact of Iron Homeostasis in Insulin-Sensitive Tissues and Gut Microbiome on Obesity-Driven Metabolic Disorders

Iron is a crucial element for vital biological processes in both prokaryotic and eukaryotic cells, requiring precise regulation to maintain homeostasis. In humans and animal models, dysregulation of iron homeostasis is often linked to obesity-associated metabolic disturbances, which are characterized by elevated serum ferritin levels and excessive iron accumulation in insulin-dependent tissues like the liver, adipose tissue, and skeletal muscle. Prolonged iron overload in tissues induces oxidative stress, which impairs insulin sensitivity and promotes systemic insulin resistance and hyperglycemia. This creates a vicious cycle in which decreased serum hepcidin levels enhance intestinal iron absorption, further exacerbating iron accumulation. While the impact of iron on gut microbiota is well established, the role of gut microbiota in regulating body iron homeostasis is less studied. Recent studies have uncovered new mechanisms by which gut microbiota influence intestinal iron absorption and the regulation of body iron stores. In this chapter, we summarize recent findings on iron homeostasis in insulin-sensitive metabolic tissues and explore how gut microbiota can modulate body iron regulation in the context of obesity.