IRS1 and obesity due to melanocortin 4 receptor deficiency: Galactose‐containing polysaccharides modulate glucose metabolism and improve insulin sensitivity, primarily by modulating gut microbiota and activating the insulin signaling pathway (IRS1/PI3K/Akt) to enhance cellular insulin response, which is crucial for maintaining energy homeostasis and preventing obesity (Le et al. 2021; Yoo et al. 2024).