Endocrine and Digestive Disorders Arising in Childhood in Down Syndrome and Their Cross-Talk

Down syndrome (DS), caused by trisomy 21, is associated with a wide spectrum of endocrine and gastrointestinal disorders that often arise early in life and significantly impact long-term health. This narrative review examines the pathophysiological mechanisms underlying these conditions, with a particular focus on their bidirectional interactions. Endocrine abnormalities in DS, including thyroid dysfunction, type 1 diabetes mellitus, growth impairment, and altered bone metabolism, occur at higher rates than in the general population and are largely driven by immune dysregulation, chronic inflammation, and gene dosage effects. Similarly, gastrointestinal disorders—ranging from congenital malformations to autoimmune conditions such as celiac disease—are highly prevalent and often present with atypical clinical features. Emerging evidence highlights the central role of gut dysbiosis, characterized by reduced microbial diversity and increased pro-inflammatory taxa, in modulating immune and metabolic pathways. This altered gut environment contributes to a chronic inflammatory state and may promote autoimmunity and endocrine dysfunction through the gut–endocrine–immune axis. Nutritional deficiencies and epigenetic factors, including microRNA dysregulation, further influence disease expression. Understanding this complex cross-talk is essential for improving clinical management. Integrated, multidisciplinary approaches and early screening strategies are crucial to optimize outcomes and guide future research in DS.