FOS and obesity due to melanocortin 4 receptor deficiency: In high‐fat diet models, combined FOS/galactooligosaccharide (GOS) supplementation alleviates obesity‐related bone loss and reverses the skewed bone marrow progenitor differentiation by enhancing osteogenesis, suppressing excessive adipogenesis, and normalizing osteoclast formation, in parallel with gut microbiota restoration, short‐chain fatty acid production, intestinal barrier integrity, and systemic inflammation (Zhang et al. 2021).